diff --git a/docs/MESHCORE.md b/docs/MESHCORE.md
index 442716e..2d701e9 100644
--- a/docs/MESHCORE.md
+++ b/docs/MESHCORE.md
@@ -37,7 +37,7 @@ Without `MESHCORE_UPLOAD_ENABLED`, `STORAGE_API_*` is ignored.
 When `MESHCORE_UPLOAD_ENABLED=true` and `STORAGE_API_*` are set, the bot also:
 
 1. **On connect** — reads the device channel table (`meshcore.commands.get_channel`) and `POST`s `/api/meshcore/feeders/{prefix}/mc-channel-sync/` (device is source of truth for names/types).
-2. **WebSocket** — connects to `ws/nodes/?api_key=…` for `apply_mc_channel_config` (UI “apply to radio”); writes channels via `set_channel`, then re-syncs to the API.
+2. **WebSocket** — connects to `ws/nodes/?api_key=…` (URL derived from `STORAGE_API_ROOT` when `MESHFLOW_WS_URL` is unset). MeshCore feeders automatically append `feeder_pubkey_prefix` from the device pubkey after connect (no env var). Used for UI **apply to radio** (`apply_mc_channel_config`): the REST endpoint only dispatches to the bot over WS; the bot writes the device via `set_channel`, then re-syncs to the API.
 
 Traceroute commands remain Meshtastic-only; MC feeders ignore `traceroute` WS messages.
 
diff --git a/src/main.py b/src/main.py
index 5491bc3..0aaf0d8 100644
--- a/src/main.py
+++ b/src/main.py
@@ -205,6 +205,11 @@ def main() -> None:
             on_apply_mc_channel_config=(
                 bot.on_apply_mc_channel_config if RADIO_PROTOCOL == "meshcore" else None
             ),
+            feeder_pubkey_prefix_provider=(
+                (lambda: getattr(radio, "feeder_mc_pubkey_prefix", None))
+                if RADIO_PROTOCOL == "meshcore"
+                else None
+            ),
         )
 
     try:
diff --git a/src/meshcore/channel_sync.py b/src/meshcore/channel_sync.py
index a3f3a1a..18fc835 100644
--- a/src/meshcore/channel_sync.py
+++ b/src/meshcore/channel_sync.py
@@ -2,9 +2,12 @@
 
 from __future__ import annotations
 
+import asyncio
 import logging
 from typing import TYPE_CHECKING, Optional
 
+CHANNEL_READ_DELAY_S = 2.0
+
 from src.meshcore.channels import (
     log_device_channels,
     read_device_channels,
@@ -31,6 +34,7 @@ async def sync_channels_to_api_async(
         channels: list[dict] = []
     else:
         try:
+            await asyncio.sleep(CHANNEL_READ_DELAY_S)
             channels = await read_device_channels(mc)
         except Exception as exc:
             logger.exception("MeshCore read_device_channels failed: %s", exc)
diff --git a/src/meshcore/channels.py b/src/meshcore/channels.py
index c430637..7595bde 100644
--- a/src/meshcore/channels.py
+++ b/src/meshcore/channels.py
@@ -33,6 +33,17 @@ def _channel_entry_from_info(idx: int, payload: dict) -> Optional[dict]:
     }
 
 
+def _describe_channel_event(idx: int, evt: Any) -> str:
+    if evt.type == EventType.ERROR:
+        payload = evt.payload if isinstance(evt.payload, dict) else {}
+        return f"[{idx}] ERROR {payload.get('reason', payload)}"
+    if evt.type == EventType.CHANNEL_INFO:
+        payload = evt.payload if isinstance(evt.payload, dict) else {}
+        name = payload.get("channel_name", "")
+        return f"[{idx}] CHANNEL_INFO name={name!r}"
+    return f"[{idx}] {evt.type}"
+
+
 async def read_device_channels(
     meshcore: MeshCore,
     *,
@@ -40,8 +51,10 @@ async def read_device_channels(
 ) -> list[dict]:
     """Return channel snapshot rows for API mc-channel-sync."""
     channels: list[dict] = []
+    scan_lines: list[str] = []
     for idx in range(max_channels):
         evt = await meshcore.commands.get_channel(idx)
+        scan_lines.append(_describe_channel_event(idx, evt))
         if evt.type == EventType.ERROR:
             continue
         if evt.type != EventType.CHANNEL_INFO:
@@ -50,6 +63,17 @@ async def read_device_channels(
         entry = _channel_entry_from_info(idx, payload)
         if entry:
             channels.append(entry)
+        elif str(payload.get("channel_name", "") or "").strip():
+            logger.info(
+                "MeshCore channel [%s] has name %r but was not mapped",
+                idx,
+                payload.get("channel_name"),
+            )
+    if not channels:
+        logger.warning(
+            "MeshCore get_channel scan found 0 named channels: %s",
+            "; ".join(scan_lines) or "(no responses)",
+        )
     return channels
 
 
diff --git a/src/ws_client.py b/src/ws_client.py
index 31f7c46..3034570 100644
--- a/src/ws_client.py
+++ b/src/ws_client.py
@@ -9,6 +9,7 @@
 import json
 import logging
 from typing import Callable, Optional
+from urllib.parse import quote
 
 logger = logging.getLogger(__name__)
 
@@ -29,6 +30,7 @@ def __init__(
         on_apply_mc_channel_config: Optional[Callable[[list], None]] = None,
         on_connect: Optional[Callable[[], None]] = None,
         on_disconnect: Optional[Callable[[], None]] = None,
+        feeder_pubkey_prefix_provider: Optional[Callable[[], Optional[str]]] = None,
     ):
         """
         Args:
@@ -44,6 +46,7 @@ def __init__(
         self.on_apply_mc_channel_config = on_apply_mc_channel_config
         self.on_connect = on_connect
         self.on_disconnect = on_disconnect
+        self._feeder_pubkey_prefix_provider = feeder_pubkey_prefix_provider
 
         self._running = False
         self._task: Optional[asyncio.Task] = None
@@ -51,7 +54,12 @@ def __init__(
         self._backoff = 1.0  # Reset on successful connect so reconnects start fast
 
     def _get_ws_endpoint(self) -> str:
-        return f"{self.ws_url}/ws/nodes/?api_key={self.api_key}"
+        url = f"{self.ws_url}/ws/nodes/?api_key={self.api_key}"
+        if self._feeder_pubkey_prefix_provider:
+            prefix = self._feeder_pubkey_prefix_provider()
+            if prefix:
+                url += f"&feeder_pubkey_prefix={quote(prefix, safe='')}"
+        return url
 
     def start(self):
         """Start the WebSocket client in a background thread."""
@@ -133,7 +141,15 @@ async def _connect_and_receive(self):
             ping_timeout=10,
         ) as ws:
             self._backoff = 1.0  # Reset so next reconnect starts with short delay
-            logger.info("MeshflowWSClient: connected")
+            prefix = (
+                self._feeder_pubkey_prefix_provider()
+                if self._feeder_pubkey_prefix_provider
+                else None
+            )
+            logger.info(
+                "MeshflowWSClient: connected (feeder_pubkey_prefix=%s)",
+                prefix or "none",
+            )
             if self.on_connect:
                 try:
                     self.on_connect()
diff --git a/test/meshcore/test_channels.py b/test/meshcore/test_channels.py
index c5c7e53..10388b7 100644
--- a/test/meshcore/test_channels.py
+++ b/test/meshcore/test_channels.py
@@ -69,6 +69,20 @@ def test_channel_entry_empty_name_returns_none() -> None:
     assert _channel_entry_from_info(0, {"channel_name": "   "}) is None
 
 
+def test_read_device_channels_logs_scan_when_empty(caplog) -> None:
+    import logging
+
+    caplog.set_level(logging.WARNING)
+    mc = MagicMock()
+    mc.commands.get_channel = AsyncMock(
+        return_value=Event(EventType.ERROR, {"reason": "not_found"}, {})
+    )
+    channels = asyncio.run(read_device_channels(mc, max_channels=2))
+    assert channels == []
+    assert "get_channel scan found 0 named channels" in caplog.text
+    assert "[0] ERROR" in caplog.text
+
+
 def test_read_device_channels_collects_public_and_skips_errors() -> None:
     mc = MagicMock()
     mc.commands.get_channel = AsyncMock(