NPE in exit transition

Android version: 10
Phone model: Huawei ELE-L29
Briar version: 1.2.9 (9d96ce6d)

Stacktrace:

java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.app.Activity.isTopOfTask()' on a null object reference
        at android.app.ExitTransitionCoordinator.notifyComplete(ExitTransitionCoordinator.java:437)
        at android.app.ExitTransitionCoordinator.onReceiveResult(ExitTransitionCoordinator.java:91)
        at android.os.ResultReceiver$MyRunnable.run(ResultReceiver.java:50)
        at android.os.Handler.handleCallback(Handler.java:900)
        at android.os.Handler.dispatchMessage(Handler.java:103)
        at android.os.Looper.loop(Looper.java:219)
        at android.app.ActivityThread.main(ActivityThread.java:8347)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1055)