diff --git a/Dockerfile.nas b/Dockerfile.nas
index 9aaa307..3689aad 100644
--- a/Dockerfile.nas
+++ b/Dockerfile.nas
@@ -10,7 +10,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     && rm -rf /var/lib/apt/lists/*
 
 # Joplin Terminal (official npm package)
-RUN npm install --loglevel=error -g joplin
+RUN npm install --loglevel=error -g joplin@3.7.1
 
 WORKDIR /app
 COPY pyproject.toml requirements.txt ./
diff --git a/nas/run_once.sh b/nas/run_once.sh
index 9b9406e..6a94847 100644
--- a/nas/run_once.sh
+++ b/nas/run_once.sh
@@ -7,6 +7,31 @@ RESULT_JSON="/app/data/last_result.json"
 
 log() { printf '%s %s\n' "$(date '+%Y-%m-%d %H:%M:%S')" "$*"; }
 fail() { log "ERROR: $*"; exit 1; }
+joplin_sync() {
+  local tmp
+  local status
+
+  tmp="$(mktemp)"
+
+  set +e
+  joplin --profile "$PROFILE" sync 2>&1 | tee "$tmp"
+  status=${PIPESTATUS[0]}
+  set -e
+
+  if [[ "$status" -ne 0 ]]; then
+    rm -f "$tmp"
+    fail "Joplin sync failed with exit code $status"
+  fi
+
+  if grep -Eqi 'Last error:|(^|[[:space:]])Error:' "$tmp"; then
+    log "ERROR: Joplin reported a sync error:"
+    grep -Ei 'Last error:|(^|[[:space:]])Error:' "$tmp" || true
+    rm -f "$tmp"
+    exit 1
+  fi
+
+  rm -f "$tmp"
+}
 
 : "${JOPLIN_WEBDAV_URL:?JOPLIN_WEBDAV_URL is required}"
 : "${JOPLIN_WEBDAV_USERNAME:?JOPLIN_WEBDAV_USERNAME is required}"
@@ -33,7 +58,7 @@ fi
 
 # Pull the current remote state first. This is important when PC/mobile also use the same WebDAV target.
 log "Synchronising Joplin from WebDAV before writing..."
-joplin --profile "$PROFILE" sync
+joplin_sync
 
 if [[ "${JOPLIN_WRITE_ENABLED,,}" != "true" ]]; then
   log "JOPLIN_WRITE_ENABLED=false: sync-only safety mode. No paper note will be written."
@@ -86,6 +111,6 @@ log "Importing report into Joplin notebook: $JOPLIN_NOTEBOOK"
 joplin --profile "$PROFILE" import "$TMP_MD" "$JOPLIN_NOTEBOOK" --format md -f
 
 log "Synchronising Joplin changes to WebDAV..."
-joplin --profile "$PROFILE" sync
+joplin_sync
 
 log "Completed: $REPORT_TITLE ($REPORT_COUNT papers)"
diff --git a/state/provider_circuit_breaker_state.json b/state/provider_circuit_breaker_state.json
index 0e28133..5be8ddf 100644
--- a/state/provider_circuit_breaker_state.json
+++ b/state/provider_circuit_breaker_state.json
@@ -10,5 +10,12 @@
     "open_until": 0.0,
     "reason": null,
     "strikes": {}
+  },
+  "ieee": {
+    "open_until": 1790933827.9323854,
+    "reason": "http_403",
+    "strikes": {
+      "http_403": 1
+    }
   }
 }
\ No newline at end of file