diff --git a/CHANGELOG.md b/CHANGELOG.md
index d078877ae..fa15e6b4f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@ All notable changes to Bambuddy will be documented in this file.
 - **Clear Plate Confirmation Bypassed on Power Cycle** ([#961](https://github.com/maziggy/bambuddy/issues/961)) — With Auto Off enabled and another job queued, the smart plug would cut power when a print finished and immediately re-power when the scheduler saw the queue, at which point the printer booted fresh into `IDLE` and the next job auto-dispatched without the "Clear Plate & Start Next" confirmation. Root cause: the plate-cleared gate lived only in the in-memory `PrinterManager._plate_cleared` set, and the scheduler's idle check treated `IDLE` as always-idle regardless of whether a previous finish had been acknowledged — so the gate was lost across both Bambuddy restarts and the IDLE-on-boot state transition. The gate is now an `awaiting_plate_clear` column on the `printers` table, set by `on_print_complete` when a print finishes or fails, cleared by the `/printers/{id}/clear-plate` endpoint and by the scheduler when it dispatches the next job, and rehydrated from the DB into `PrinterManager` on startup. `_is_printer_idle` now short-circuits to not-idle whenever `require_plate_clear` is on and the printer is awaiting ack, regardless of the currently reported state — so the prompt survives Auto Off cycles, Bambuddy restarts, and the printer booting back into `IDLE`. The clear-plate endpoint no longer requires the printer to currently report `FINISH`/`FAILED` (it accepts the ack whenever the awaiting flag is set), and the Printers page widget prompts based on the flag rather than the reported state. Thanks to @miaopas for reporting.
 - **Insecure Temp File Creation in Backup Export** — The manual backup download endpoint used `tempfile.mktemp()`, which is vulnerable to a symlink race condition (CWE-377). Replaced with `tempfile.mkstemp()` which atomically creates the file, eliminating the TOCTOU window.
 - **Spoolman Iframe Blocked After 0.2.3b4 Security Headers** — The Spoolman page (Inventory → Spoolman iframe) failed to load when Spoolman was served from the same host as Bambuddy via a reverse proxy. The security-headers middleware added in 0.2.3b4 set `X-Frame-Options: DENY` on every response, which blocked even same-origin iframing. Relaxed to `SAMEORIGIN` so Spoolman (and any other same-origin tool behind the same reverse proxy) can be embedded again, while still preventing cross-origin clickjacking.
+- **SD Card Badge Flapping on H2D** — The new SD card status badge on the Printers page card toggled between "inserted" (green) and "not inserted" (red) every few seconds on H2D. Root cause: the MQTT parser used a strict identity check (`data["sdcard"] is True`) on the top-level `sdcard` field, but real firmware ships that field inconsistently — bool on some models, int `1`, or a string enum like `"HAS_SDCARD_NORMAL"` on others — so any message carrying a non-bool value flipped the state to `False`. Fixed by deriving the badge from `home_flag` bits 8–9 (`HAS_SDCARD_NORMAL` / `HAS_SDCARD_ABNORMAL`) when present — the canonical firmware source, same as door and store-to-SD parsing — and falling back to a truthy check on the top-level field for firmwares that only send that.
 - **CSP Blocked Sidebar Iframes, Service-Worker Registration, and Google Fonts** — The strict `Content-Security-Policy` header added in 0.2.3b4 broke three things at once: (1) custom sidebar links pointing at external HTTPS URLs (e.g. a Grafana/telemetry dashboard) rendered in `ExternalLinkPage` were blocked because no `frame-src` was declared and iframes fell back to `default-src 'self'`; (2) the inline service-worker registration `<script>` at the bottom of `index.html` was blocked by `script-src 'self'`, silently preventing the PWA service worker from installing; (3) the `@import` of Google Fonts' Inter from `index.css` was blocked by `style-src` and `font-src`. Fixed by adding `frame-src 'self' https:` for user-configured HTTPS iframe targets, moving the inline SW-registration script into `/sw-register.js` so `script-src 'self'` covers it without needing `'unsafe-inline'` or per-build hashes, and allowing `https://fonts.googleapis.com` in `style-src` and `https://fonts.gstatic.com` in `font-src`. `frame-ancestors 'none'` is preserved so Bambuddy itself still cannot be framed cross-origin.
 
 
diff --git a/backend/app/services/bambu_mqtt.py b/backend/app/services/bambu_mqtt.py
index c9b665c5e..5301a6b35 100644
--- a/backend/app/services/bambu_mqtt.py
+++ b/backend/app/services/bambu_mqtt.py
@@ -2237,17 +2237,30 @@ class BambuMQTTClient:
                             )
                         )
 
-        # Parse SD card status
-        if "sdcard" in data:
-            self.state.sdcard = data["sdcard"] is True
-
-        # Parse home_flag for "Store Sent Files on External Storage" setting (bit 11)
+        # Parse home_flag first so SD-card detection below can prefer it.
+        # Bit 8 = HAS_SDCARD_NORMAL, bit 9 = HAS_SDCARD_ABNORMAL, bit 11 = store-to-SD,
+        # bit 23 = door-open (X1 family only).
+        home_flag = None
         if "home_flag" in data:
             home_flag = data["home_flag"]
-            # Bit 11 controls "Store Sent Files on External Storage"
-            # Convert to unsigned 32-bit if negative
             if home_flag < 0:
                 home_flag = home_flag & 0xFFFFFFFF
+
+        # Parse SD card status. Canonical source on real firmware is home_flag bits 8-9;
+        # the top-level `sdcard` field is firmware-dependent (bool on some models, string
+        # enum like "HAS_SDCARD_NORMAL" on others), so strict identity checks caused the
+        # badge to flap on H2D. Prefer home_flag when available, fall back to a truthy
+        # check on the `sdcard` field for firmwares that only send that.
+        if home_flag is not None:
+            self.state.sdcard = ((home_flag >> 8) & 0x3) != 0
+        elif "sdcard" in data:
+            raw_sdcard = data["sdcard"]
+            if isinstance(raw_sdcard, str):
+                self.state.sdcard = "HAS_SDCARD" in raw_sdcard.upper() or raw_sdcard.lower() in ("true", "normal", "1")
+            else:
+                self.state.sdcard = bool(raw_sdcard)
+
+        if home_flag is not None:
             store_to_sdcard = bool((home_flag >> 11) & 1)
             if store_to_sdcard != self.state.store_to_sdcard:
                 logger.debug(
@@ -2261,7 +2274,7 @@ class BambuMQTTClient:
         # Both share the same bitmask (0x00800000) but live in different fields.
         model_upper = (self.model or "").upper().strip()
         is_x1_family = model_upper in ("X1", "X1C", "X1E")
-        if is_x1_family and "home_flag" in data:
+        if is_x1_family and home_flag is not None:
             door_open = (home_flag & 0x00800000) != 0
             if door_open != self.state.door_open:
                 logger.debug(
diff --git a/backend/tests/unit/services/test_bambu_mqtt.py b/backend/tests/unit/services/test_bambu_mqtt.py
index 55705e185..c90268904 100644
--- a/backend/tests/unit/services/test_bambu_mqtt.py
+++ b/backend/tests/unit/services/test_bambu_mqtt.py
@@ -3574,3 +3574,61 @@ class TestDoorOpenParsing:
         client = self._make_client("H2D")
         client._update_state({"stat": "not-hex"})
         assert client.state.door_open is False
+
+
+class TestSdCardParsing:
+    """SD-card state is derived from home_flag bits 8-9 when present, else from
+    the top-level `sdcard` field (which firmware may send as bool, int, or string)."""
+
+    def _make_client(self, model: str = "H2D"):
+        from backend.app.services.bambu_mqtt import BambuMQTTClient
+
+        return BambuMQTTClient(
+            ip_address="192.168.1.100",
+            serial_number="TEST",
+            access_code="12345678",
+            model=model,
+        )
+
+    def test_home_flag_bit8_sets_sdcard_true(self):
+        client = self._make_client()
+        client._update_state({"home_flag": 0x00000100})  # bit 8
+        assert client.state.sdcard is True
+
+    def test_home_flag_bit9_sets_sdcard_true(self):
+        # Abnormal-but-present still counts as inserted for the badge
+        client = self._make_client()
+        client._update_state({"home_flag": 0x00000200})  # bit 9
+        assert client.state.sdcard is True
+
+    def test_home_flag_no_sdcard_bits(self):
+        client = self._make_client()
+        client.state.sdcard = True
+        client._update_state({"home_flag": 0x00000000})
+        assert client.state.sdcard is False
+
+    def test_home_flag_wins_over_sdcard_field(self):
+        # Real firmware can send `sdcard` as a non-bool; home_flag must still win.
+        client = self._make_client()
+        client._update_state({"home_flag": 0x00000100, "sdcard": "HAS_SDCARD_NORMAL"})
+        assert client.state.sdcard is True
+        client._update_state({"home_flag": 0x00000000, "sdcard": 1})
+        assert client.state.sdcard is False
+
+    def test_sdcard_string_fallback_when_no_home_flag(self):
+        client = self._make_client()
+        client._update_state({"sdcard": "HAS_SDCARD_NORMAL"})
+        assert client.state.sdcard is True
+
+    def test_sdcard_int_fallback_when_no_home_flag(self):
+        # `1 is True` is False — the old strict check flapped here.
+        client = self._make_client()
+        client._update_state({"sdcard": 1})
+        assert client.state.sdcard is True
+
+    def test_sdcard_bool_fallback_when_no_home_flag(self):
+        client = self._make_client()
+        client._update_state({"sdcard": True})
+        assert client.state.sdcard is True
+        client._update_state({"sdcard": False})
+        assert client.state.sdcard is False