Android crash before chat initialization

Hi support team,

I have a bug will happen every time.

start intent ZopimChatActivity, then press back before the chat session initialize complete.

Then the crash happen.

 java.lang.RuntimeException: An error occurred while executing doInBackground()
        at android.os.AsyncTask$4.done(AsyncTask.java:415)
        at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:383)
        at java.util.concurrent.FutureTask.setException(FutureTask.java:252)
        at java.util.concurrent.FutureTask.run(FutureTask.java:271)
        at com.zopim.android.sdk.data.SerialExecutor$1.run(SerialExecutor.java:29)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
        at java.lang.Thread.run(Thread.java:923)
     Caused by: java.lang.IllegalStateException: Method removeObserver must be called on the main thread
        at androidx.lifecycle.LifecycleRegistry.enforceMainThreadIfNeeded(LifecycleRegistry.java:317)
        at androidx.lifecycle.LifecycleRegistry.removeObserver(LifecycleRegistry.java:219)
        at com.zopim.android.sdk.api.ChatClient.endChat(ChatClient.java:260)
        at com.zopim.android.sdk.api.ChatClient$InitializationConnectionObserver.resendUnsentIntents(ChatClient.java:731)
        at com.zopim.android.sdk.api.ChatClient$InitializationConnectionObserver.update(ChatClient.java:659)
        at com.zopim.android.sdk.data.observers.ConnectionObserver.update(ConnectionObserver.java:21)
        at java.util.Observable.notifyObservers(Observable.java:163)
        at com.zopim.android.sdk.data.Path.broadcast(Path.java:108)
        at com.zopim.android.sdk.data.ConnectionPath.update(ConnectionPath.java:59)
        at com.zopim.android.sdk.data.PathUpdater.updatePath(PathUpdater.java:56)
        at com.zopim.android.sdk.data.PathUpdaterTask.doInBackground(PathUpdaterTask.java:18)
        at com.zopim.android.sdk.data.PathUpdaterTask.doInBackground(PathUpdaterTask.java:8)
        at android.os.AsyncTask$3.call(AsyncTask.java:394)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at com.zopim.android.sdk.data.SerialExecutor$1.run(SerialExecutor.java:29) 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641) 
        at java.lang.Thread.run(Thread.java:923) 

I have already upgrade the sdk version as below(Should be same version as the sample)

"com.zendesk:support:5.0.3"
"com.zopim.android:sdk:1.4.9"

Seems the crash is inside the sdk and I have no idea to fix the bug.

Does anyone have the same issue? Or any suggestion? Thank you.