It seems that annotating the lambda makes the thread check works

app/src/main/java/org/linphone/core/CoreContext.kt

@@ -214,14 +214,18 @@ class CoreContext @UiThread constructor(val context: Context) : HandlerThread("C
     }
 
     @AnyThread
-    fun postOnCoreThread(lambda: (core: Core) -> Unit) {
+    fun postOnCoreThread(
+        @WorkerThread lambda: (core: Core) -> Unit
+    ) {
         coreThread.post {
             lambda.invoke(core)
         }
     }
 
     @AnyThread
-    fun postOnMainThread(lambda: () -> Unit) {
+    fun postOnMainThread(
+        @UiThread lambda: () -> Unit
+    ) {
         mainThread.post {
             lambda.invoke()
         }

app/src/main/java/org/linphone/telecom/TelecomCallControlCallback.kt

@@ -20,6 +20,7 @@
 package org.linphone.telecom
 
 import android.telecom.DisconnectCause
+import androidx.annotation.WorkerThread
 import androidx.core.telecom.CallAttributesCompat
 import androidx.core.telecom.CallControlResult
 import androidx.core.telecom.CallControlScope
@@ -48,6 +49,7 @@ class TelecomCallControlCallback constructor(
     private var availableEndpoints: List<CallEndpointCompat> = arrayListOf()
 
     private val callListener = object : CallListenerStub() {
+        @WorkerThread
         override fun onStateChanged(call: Call, state: Call.State?, message: String) {
             Log.i("$TAG Call [${call.remoteAddress.asStringUriOnly()}] state changed [$state]")
             if (state == Call.State.Connected) {

app/src/main/java/org/linphone/ui/call/model/CallModel.kt

@@ -47,6 +47,7 @@ class CallModel @WorkerThread constructor(val call: Call) {
     val contact = MutableLiveData<ContactAvatarModel>()
 
     private val callListener = object : CallListenerStub() {
+        @WorkerThread
         override fun onStateChanged(call: Call, state: Call.State, message: String) {
             this@CallModel.state.postValue(LinphoneUtils.callStateToString(state))
             isPaused.postValue(LinphoneUtils.isCallPaused(state))