diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 19ff23571..ab6da34e8 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -4,7 +4,6 @@ name: Lint
 
 env:
   HADOLINT_VERSION: v1.17.2
-  SHELLCHECK_OPTS: -e SC1008 -s bash
 
 on:
   pull_request:
@@ -50,6 +49,8 @@ jobs:
 
       - name: Run linter
         uses: ludeeus/action-shellcheck@2.0.0
+        env:
+          SHELLCHECK_OPTS: -e SC1008 -s bash -x
         with:
           # Names of scripts with custom shebangs that the action would not
           # discover on its own:
diff --git a/openthread_border_router/CHANGELOG.md b/openthread_border_router/CHANGELOG.md
index 745b10773..8381cf6b7 100644
--- a/openthread_border_router/CHANGELOG.md
+++ b/openthread_border_router/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## 2.16.6
+
+- Fix and improve NAT64 firewall rules
+- Enable recovery mechanism from "radio tx timeout" errors for beta
+- Narrow non-firewall forwarding rules to Thread interface
+
 ## 2.16.5
 
 - Add `backbone_interface` option to override the network interface used for IPv6 routing.
diff --git a/openthread_border_router/Dockerfile b/openthread_border_router/Dockerfile
index 6564f3118..93822eba5 100644
--- a/openthread_border_router/Dockerfile
+++ b/openthread_border_router/Dockerfile
@@ -62,6 +62,7 @@ RUN \
         -DOT_COAPS=OFF \
         -DOT_THREAD_VERSION=1.4 \
         -DOT_PROJECT_CONFIG="/usr/src/ot-br-posix/third_party/openthread/repo/openthread-core-ha-config-posix.h" \
+        -DOT_RCP_RESTORATION_MAX_COUNT=2 \
     && cd /usr/src/ot-br-posix/build/otbr \
     && ninja install
 
diff --git a/openthread_border_router/config.yaml b/openthread_border_router/config.yaml
index 99c8ae103..33f950694 100644
--- a/openthread_border_router/config.yaml
+++ b/openthread_border_router/config.yaml
@@ -1,5 +1,5 @@
 ---
-version: 2.16.5
+version: 2.16.6
 slug: openthread_border_router
 name: OpenThread Border Router
 description: OpenThread Border Router add-on
diff --git a/openthread_border_router/rootfs/etc/s6-overlay/s6-rc.d/otbr-agent/finish b/openthread_border_router/rootfs/etc/s6-overlay/s6-rc.d/otbr-agent/finish
index 7ece6a29d..5c1039bee 100755
--- a/openthread_border_router/rootfs/etc/s6-overlay/s6-rc.d/otbr-agent/finish
+++ b/openthread_border_router/rootfs/etc/s6-overlay/s6-rc.d/otbr-agent/finish
@@ -16,7 +16,7 @@ else
     bashio::log.info "otbr-agent exited with code $e (by signal $2)."
 fi
 
-# shellcheck disable=SC1091
+# shellcheck source=./openthread_border_router/rootfs/etc/s6-overlay/scripts/otbr-agent-common
 . /etc/s6-overlay/scripts/otbr-agent-common
 
 ipset_destroy_if_exist()
@@ -28,16 +28,13 @@ ipset_destroy_if_exist()
     done
 }
 
-# shellcheck disable=SC2154,SC2086
-while ip6tables -C FORWARD -o $thread_if -j $otbr_forward_ingress_chain 2> /dev/null; do
-    # shellcheck disable=SC2086
-    ip6tables -D FORWARD -o $thread_if -j $otbr_forward_ingress_chain
+while ip6tables -C FORWARD -o "${thread_if}" -j "${otbr_forward_ingress_chain}" 2> /dev/null; do
+    ip6tables -D FORWARD -o "${thread_if}" -j "${otbr_forward_ingress_chain}"
 done
 
-# shellcheck disable=SC2086
-if ip6tables -L $otbr_forward_ingress_chain 2> /dev/null; then
-    ip6tables -w -F $otbr_forward_ingress_chain
-    ip6tables -w -X $otbr_forward_ingress_chain
+if ip6tables -L "${otbr_forward_ingress_chain}" 2> /dev/null; then
+    ip6tables -w -F "${otbr_forward_ingress_chain}"
+    ip6tables -w -X "${otbr_forward_ingress_chain}"
 fi
 
 ipset_destroy_if_exist otbr-ingress-deny-src
@@ -45,17 +42,35 @@ ipset_destroy_if_exist otbr-ingress-deny-src-swap
 ipset_destroy_if_exist otbr-ingress-allow-dst
 ipset_destroy_if_exist otbr-ingress-allow-dst-swap
 
-# shellcheck disable=SC2154,SC2086
-while ip6tables -C FORWARD -i $thread_if -j $otbr_forward_egress_chain 2> /dev/null; do
-    ip6tables -D FORWARD -i $thread_if -j $otbr_forward_egress_chain
+while ip6tables -C FORWARD -i "${thread_if}" -j "${otbr_forward_egress_chain}" 2> /dev/null; do
+    ip6tables -D FORWARD -i "${thread_if}" -j "${otbr_forward_egress_chain}"
 done
 
-# shellcheck disable=SC2086
-if ip6tables -L $otbr_forward_egress_chain 2> /dev/null; then
-    ip6tables -w -F $otbr_forward_egress_chain
-    ip6tables -w -X $otbr_forward_egress_chain
+if ip6tables -L "${otbr_forward_egress_chain}" 2> /dev/null; then
+    ip6tables -w -F "${otbr_forward_egress_chain}"
+    ip6tables -w -X "${otbr_forward_egress_chain}"
 fi
-bashio::log.info "OTBR firewall teardown completed."
+
+# Remove FORWARD jump(s)
+while iptables -C FORWARD -j "${otbr_forward_nat64_chain}" 2>/dev/null; do
+    iptables -D FORWARD -j "${otbr_forward_nat64_chain}"
+done
+
+# Flush and delete chain
+if iptables -L "${otbr_forward_nat64_chain}" -n 2>/dev/null; then
+    iptables -w -F "${otbr_forward_nat64_chain}"
+    iptables -w -X "${otbr_forward_nat64_chain}"
+fi
+
+# Clean mangle and nat rules
+while iptables -t mangle -C PREROUTING -i "${thread_if}" -j MARK --set-mark "${otbr_fw_mark}" 2>/dev/null; do
+    iptables -t mangle -D PREROUTING -i "${thread_if}" -j MARK --set-mark "${otbr_fw_mark}"
+done
+
+while iptables -t nat -C POSTROUTING -m mark --mark "${otbr_fw_mark}" -j MASQUERADE 2>/dev/null; do
+    iptables -t nat -D POSTROUTING -m mark --mark "${otbr_fw_mark}" -j MASQUERADE
+done
+bashio::log.info "OTBR firewall/NAT64 rules teardown completed."
 
 if test "$e" -ne 0; then
     echo "$e" > /run/s6-linux-init-container-results/exitcode
diff --git a/openthread_border_router/rootfs/etc/s6-overlay/s6-rc.d/otbr-agent/run b/openthread_border_router/rootfs/etc/s6-overlay/s6-rc.d/otbr-agent/run
index 26d1bf9b4..ead6314fc 100755
--- a/openthread_border_router/rootfs/etc/s6-overlay/s6-rc.d/otbr-agent/run
+++ b/openthread_border_router/rootfs/etc/s6-overlay/s6-rc.d/otbr-agent/run
@@ -5,7 +5,7 @@
 # OpenThread BorderRouter start script
 # ==============================================================================
 
-# shellcheck disable=SC1091
+# shellcheck source=./openthread_border_router/rootfs/etc/s6-overlay/scripts/otbr-agent-common
 . /etc/s6-overlay/scripts/otbr-agent-common
 
 declare backbone_if
@@ -96,45 +96,43 @@ ipset create -exist otbr-ingress-deny-src-swap hash:net family inet6
 ipset create -exist otbr-ingress-allow-dst hash:net family inet6
 ipset create -exist otbr-ingress-allow-dst-swap hash:net family inet6
 
+ip6tables -N "${otbr_forward_ingress_chain}"
+ip6tables -I FORWARD 1 -o "${thread_if}" -j "${otbr_forward_ingress_chain}"
+
+ip6tables -N "${otbr_forward_egress_chain}"
+ip6tables -I FORWARD 2 -i "${thread_if}" -j "${otbr_forward_egress_chain}"
+
 if bashio::config.true 'firewall'; then
     bashio::log.info "Setup OTBR firewall..."
-# shellcheck disable=SC2086,SC2154
-    ip6tables -N $otbr_forward_ingress_chain
-# shellcheck disable=SC2086,SC2154
-    ip6tables -I FORWARD 1 -o $thread_if -j $otbr_forward_ingress_chain
-
-    # shellcheck disable=SC2086
-    ip6tables -A $otbr_forward_ingress_chain -m pkttype --pkt-type unicast -i ${thread_if} -j DROP
-    # shellcheck disable=SC2086
-    ip6tables -A $otbr_forward_ingress_chain -m set --match-set otbr-ingress-deny-src src -j DROP
-    # shellcheck disable=SC2086
-    ip6tables -A $otbr_forward_ingress_chain -m set --match-set otbr-ingress-allow-dst dst -j ACCEPT
-    # shellcheck disable=SC2086
-    ip6tables -A $otbr_forward_ingress_chain -m pkttype --pkt-type unicast -j DROP
-    # shellcheck disable=SC2086
-    ip6tables -A $otbr_forward_ingress_chain -j ACCEPT
-
-    # shellcheck disable=SC2086,SC2154
-    ip6tables -N $otbr_forward_egress_chain
-    # shellcheck disable=SC2086
-    ip6tables -I FORWARD 2 -i $thread_if -j $otbr_forward_egress_chain
-    # shellcheck disable=SC2086
-    ip6tables -A $otbr_forward_egress_chain -j ACCEPT
+
+    ip6tables -A "${otbr_forward_ingress_chain}" -m pkttype --pkt-type unicast -i "${thread_if}" -j DROP
+    ip6tables -A "${otbr_forward_ingress_chain}" -m set --match-set otbr-ingress-deny-src src -j DROP
+    ip6tables -A "${otbr_forward_ingress_chain}" -m set --match-set otbr-ingress-allow-dst dst -j ACCEPT
+    ip6tables -A "${otbr_forward_ingress_chain}" -m pkttype --pkt-type unicast -j DROP
+    ip6tables -A "${otbr_forward_ingress_chain}" -j ACCEPT
+
+    ip6tables -A "${otbr_forward_egress_chain}" -j ACCEPT
 else
-    # Make sure ip6tables (as used by Docker) allow IP forwarding
-    ip6tables -P FORWARD ACCEPT
-    # HAOS 9.3 and earlier (for 9.4 accept is the default so this won't do anything)
-    ip6tables-legacy -P FORWARD ACCEPT
+    ip6tables -A "${otbr_forward_ingress_chain}" -j ACCEPT
+
+    ip6tables -A "${otbr_forward_egress_chain}" -j ACCEPT
 fi
 
 if bashio::config.true 'nat64'; then
-    # shellcheck disable=SC2086
-    iptables -t mangle -A PREROUTING -i ${thread_if} -j MARK --set-mark 0x1001
-    iptables -t nat -A POSTROUTING -m mark --mark 0x1001 -j MASQUERADE
-    # shellcheck disable=SC2086
-    iptables -t filter -A FORWARD -o ${backbone_if} -j ACCEPT
-    # shellcheck disable=SC2086
-    iptables -t filter -A FORWARD -i ${backbone_if} -j ACCEPT
+    # Mark Thread traffic in mangle
+    iptables -t mangle -A PREROUTING -i "${thread_if}" -j MARK --set-mark "${otbr_fw_mark}"
+
+    # MASQUERADE marked traffic
+    iptables -t nat -A POSTROUTING -m mark --mark "${otbr_fw_mark}" -j MASQUERADE
+
+    # NAT64 forward chain — jump unconditionally, filter inside
+    iptables -N "${otbr_forward_nat64_chain}"
+    iptables -I FORWARD 1 -j "${otbr_forward_nat64_chain}"
+
+    # Forward marked traffic
+    iptables -A "${otbr_forward_nat64_chain}" -m mark --mark "${otbr_fw_mark}" -o "${backbone_if}" -j ACCEPT
+    # Use conntrack to identify return traffic
+    iptables -A "${otbr_forward_nat64_chain}" -m conntrack --ctstate ESTABLISHED,RELATED -i "${backbone_if}" -o "${thread_if}" -j ACCEPT
 fi
 
 otbr_rest_listen="::"
diff --git a/openthread_border_router/rootfs/etc/s6-overlay/scripts/otbr-agent-common b/openthread_border_router/rootfs/etc/s6-overlay/scripts/otbr-agent-common
index e4d4669a9..54b17c140 100644
--- a/openthread_border_router/rootfs/etc/s6-overlay/scripts/otbr-agent-common
+++ b/openthread_border_router/rootfs/etc/s6-overlay/scripts/otbr-agent-common
@@ -1,9 +1,14 @@
-#!/bin/sh
+# shellcheck shell=bash
+# shellcheck disable=SC2034
 
 declare thread_if
 declare otbr_forward_ingress_chain
 declare otbr_forward_egress_chain
+declare otbr_forward_nat64_chain
+declare otbr_fw_mark
 thread_if="wpan0"
 otbr_forward_ingress_chain="OTBR_FORWARD_INGRESS"
 otbr_forward_egress_chain="OTBR_FORWARD_EGRESS"
+otbr_forward_nat64_chain="OTBR_FORWARD_NAT64"
+otbr_fw_mark="0x1001"