firebase-android-sdk: ANR at com.google.internal.firebase.inappmessaging.v1.sdkserving.InAppMessagingSdkServingGrpc$InAppMessagingSdkServingBlockingStub.fetchEligibleCampaigns (InAppMessagingSdkServingGrpc.java:222)

[READ] Step 1: Are you in the right place?

Issues filed here should be about bugs in the code in this repository. If you have a general question, need help debugging, or fall into some other category use one of these other channels:

• For general technical questions, post a question on StackOverflow with the firebase tag.
• For general Firebase discussion, use the firebase-talk google group.
• For help troubleshooting your application that does not fall under one of the above categories, reach out to the personalized Firebase support channel.

[REQUIRED] Step 2: Describe your environment

• Android Studio version: 3.4.1 ->3.6.1
• Firebase Component: firebase-inappmessaging-display
• Component version: 19.0.4

[REQUIRED] Step 3: Describe the problem

Steps to reproduce:

This is shown as an ANR report. The problem is happening only in one version after “Downgrade to SDKs that use a version of Firebase InstanceId before v20.1.0. The easiest way to do this is to depend on Firebase Messaging v20.1.0 (or before) and lock the version of Firebase InstanceId to v20.0.2 in your Gradle file.” as suggested in #1339

These were the only changes:

classpath com.android.tools.build:gradle: 3.4.1 ->3.6.1 classpath io.fabric.tools:gradle: 1.28.1 -> 1.31.2

com.google.firebase:firebase-messaging: 20.1.3 -> 20.1.0 added explicit com.google.firebase:firebase-iid:20.0.2 implementation('com.crashlytics.sdk.android:crashlytics: 2.5.2 -> 2.10.1 ') { transitive = true }

Relevant Code:

"main" prio=5 tid=1 Waiting
  | group="main" sCount=1 dsCount=0 flags=1 obj=0x74695990 self=0x6f34014c00
  | sysTid=26280 nice=-10 cgrp=default sched=0/0 handle=0x6fba84e548
  | state=S schedstat=( 65587206081 31035698087 209749 ) utm=5200 stm=1358 core=6 HZ=100
  | stack=0x7fe1ffc000-0x7fe1ffe000 stackSize=8MB
  | held mutexes=
  at java.lang.Object.wait (Object.java)
- waiting on <0x02c37e9f> (a java.lang.Object)
  at java.lang.Thread.parkFor$ (Thread.java:2137)
- locked <0x02c37e9f> (a java.lang.Object)
  at sun.misc.Unsafe.park (Unsafe.java:358)
  at java.util.concurrent.locks.LockSupport.park (LockSupport.java:190)
  at io.grpc.stub.ClientCalls$ThreadlessExecutor.waitAndDrain (ClientCalls.java:660)
  at io.grpc.stub.ClientCalls.blockingUnaryCall (ClientCalls.java:132)
  at com.google.internal.firebase.inappmessaging.v1.sdkserving.InAppMessagingSdkServingGrpc$InAppMessagingSdkServingBlockingStub.fetchEligibleCampaigns (InAppMessagingSdkServingGrpc.java:222)
  at com.google.firebase.inappmessaging.internal.GrpcClient.fetchEligibleCampaigns (GrpcClient.java:38)
  at com.google.firebase.inappmessaging.internal.ApiClient.lambda$getFiams$0 (ApiClient.java:104)
  at com.google.firebase.inappmessaging.internal.ApiClient$$Lambda$1.then (ApiClient.java:5222)
  at com.google.android.gms.tasks.zzd.run (zzd.java:5)
  at android.os.Handler.handleCallback (Handler.java:873)
  at android.os.Handler.dispatchMessage (Handler.java:99)
  at android.os.Looper.loop (Looper.java:193)
  at android.app.ActivityThread.main (ActivityThread.java:6715)
  at java.lang.reflect.Method.invoke (Method.java)
  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:493)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:911)