diff --git a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/CallAudioRouter.kt b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/CallAudioRouter.kt
index 77a22e36..f17ebd75 100644
--- a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/CallAudioRouter.kt
+++ b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/CallAudioRouter.kt
@@ -330,7 +330,11 @@ class CallAudioRouter {
     /* ── мониторинг гарнитуры ── */
     private fun onDevicesChanged() {
         if (!started) return
+        val previous = devices?.map { "${it.id}/${it.type}/${it.isSink}/${it.isSource}" }?.sorted()
         devices = am.getDevices(AudioManager.GET_DEVICES_ALL)
+        val current = devices?.map { "${it.id}/${it.type}/${it.isSink}/${it.isSource}" }?.sorted()
+        if (previous != current) LogManager.addLog("INFO", "CallAudioRouter",
+            "devices changed id/type/output/input=$current telecomHeadset=${telecom?.headsetAvailable} route=$route")
         /* если в режиме HEADSET появилось SCO-устройство — пере-применяем маршрут,
          * иначе SCO не замаршрутизируется автоматически */
         if (telecom == null && route == AudioRoute.HEADSET) applyRoute(route)
diff --git a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/UtunConnection.kt b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/UtunConnection.kt
index d377eade..07722438 100644
--- a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/UtunConnection.kt
+++ b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/UtunConnection.kt
@@ -108,10 +108,12 @@ class UtunConnection(
     }
 
     override fun onAvailableCallEndpointsChanged(availableEndpoints: MutableList<CallEndpoint>) {
+        val changed = this.availableEndpoints.map { it.identifier to it.endpointType }.toSet() !=
+            availableEndpoints.map { it.identifier to it.endpointType }.toSet()
         this.availableEndpoints.clear()
         this.availableEndpoints.addAll(availableEndpoints)
-        LogManager.addLog("DEBUG", "UtunConn",
-            "availableEndpoints -> %s".format(availableEndpoints.joinToString { "${it.endpointName}/${it.endpointType}" }))
+        if (changed) LogManager.addLog("INFO", "UtunConn",
+            "endpoints id=$callId types=${availableEndpoints.map { it.endpointType }} headset=$headsetAvailable confirmed=$confirmedRoute")
         onEndpointsChanged?.invoke()
         wantedRoute?.let { routeTo(it) }
     }
diff --git a/tools/chatgui-android/audio-probe/src/main/cpp/probe.cpp b/tools/chatgui-android/audio-probe/src/main/cpp/probe.cpp
index 2e4b07bb..083fb6c2 100644
--- a/tools/chatgui-android/audio-probe/src/main/cpp/probe.cpp
+++ b/tools/chatgui-android/audio-probe/src/main/cpp/probe.cpp
@@ -13,6 +13,7 @@ struct Probe {
     int channels = 0;
     std::atomic<int> error{0}, callbacks{0}, callbackFrames{0};
     int previousError = 0;
+    int previousBuffer = -1;
 };
 static Probe probe;
 
@@ -60,6 +61,7 @@ extern "C" JNIEXPORT jboolean JNICALL Java_com_utun_audioprobe_ProbeActivity_ope
         return JNI_FALSE;
     }
     probe.channels = channels; probe.error = 0; probe.callbacks = 0; probe.callbackFrames = 0; probe.previousError = 0;
+    probe.previousBuffer = -1;
     AAudioStreamBuilder* builder = nullptr;
     if (!check_result("builder", AAudio_createStreamBuilder(&builder))) return JNI_FALSE;
     AAudioStreamBuilder_setDirection(builder, AAUDIO_DIRECTION_OUTPUT);
@@ -100,9 +102,12 @@ extern "C" JNIEXPORT jboolean JNICALL Java_com_utun_audioprobe_ProbeActivity_ope
 }
 
 extern "C" JNIEXPORT jint JNICALL Java_com_utun_audioprobe_ProbeActivity_writeNative(JNIEnv* env, jclass, jshortArray input) {
+    int64_t queued = AAudioStream_getFramesWritten(probe.stream) - AAudioStream_getFramesRead(probe.stream);
+    int available = int(std::max<int64_t>(0, AAudioStream_getBufferSizeInFrames(probe.stream) - queued));
+    if (!available) return AAudioStream_getState(probe.stream) == AAUDIO_STREAM_STATE_DISCONNECTED ? AAUDIO_ERROR_DISCONNECTED : 0;
     int16_t samples[960]{};
     env->GetShortArrayRegion(input, 0, 960, samples);
-    return AAudioStream_write(probe.stream, samples, 960 / probe.channels, 0);
+    return AAudioStream_write(probe.stream, samples, std::min(available, 960 / probe.channels), 0);
 }
 
 /* Timestamp опрашивается вне realtime callback. Java одинаково агрегирует AAudio и AudioTrack. */
@@ -111,6 +116,12 @@ extern "C" JNIEXPORT void JNICALL Java_com_utun_audioprobe_ProbeActivity_sampleN
         DEBUG_ERROR(DEBUG_CATEGORY_CALL, "probe invalid sample"); return;
     }
     auto* s = probe.stream;
+    int buffer = AAudioStream_getBufferSizeInFrames(s);
+    if (buffer != probe.previousBuffer) {
+        DEBUG_INFO(DEBUG_CATEGORY_CALL, "probe buffer=%d capacity=%d written=%lld read=%lld", buffer,
+            AAudioStream_getBufferCapacityInFrames(s), (long long)AAudioStream_getFramesWritten(s), (long long)AAudioStream_getFramesRead(s));
+        probe.previousBuffer = buffer;
+    }
     int64_t frame = -1, stamp = -1;
     int64_t written = AAudioStream_getFramesWritten(s);
     int result = AAudioStream_getTimestamp(s, CLOCK_MONOTONIC, &frame, &stamp);