diff --git a/opencode/decisions.yaml b/opencode/decisions.yaml
index 5c5d17f5..3c27cd53 100644
--- a/opencode/decisions.yaml
+++ b/opencode/decisions.yaml
@@ -456,3 +456,23 @@ notes:
       - matter
     pin: true
     status: active
+  - id: 2026-08-23-thread-outage-fix-cold-boot-google-tv
+    date: 2026-08-23
+    title: "Thread outage fix: cold-boot Google TV Streamer"
+    decision: "If Matter/Thread nodes go unavailable after network disruption: unplug+replug
+      the Google TV Streamer (Thread BR), wait ~10 min. Nodes rejoin only if cold boot
+      restores its original Thread dataset; else re-pair needed. Restarting HA/Matter
+      add-on does NOT help."
+    rationale: "2026-08-23: Bell router reboot made TV Streamer re-form Thread mesh under new
+      identity (XPAN BDE139547AD960A4 / fdbd:e139:547a:60a4); six Thread nodes stranded on
+      dead fd25:f6c0:5149 formation — silent, invisible to mDNS. Add-on restart useless;
+      cold boot restored dataset by 18:25. Google never exports credentials; permanent fix
+      = HA-hosted OTBR on own radio."
+    entities:
+      - light.bedroom_lamp
+      - light.office_lamp
+      - sensor.bedroom_switch_battery
+    integrations:
+      - matter
+      - thread
+    status: active