app unresponsive after return from sleep mode

Description

I use the android app at evening to listen to some music while fell asleep. The timer works great, but the app seems to enter an bad state after it pause. If I unlock the phone again and press the 'next track' button at the apps miniplayer at the android message menu, the app crashes. If I enter the app directly, I can't start playback or skip tracks. The buttons just don't start the actions.

Expected behavior

After stopping playback the app should behave like normal and stay responsive.

Actual behavior

The app crashes or doesn't play anymore.

Steps to reproduce

1. Load some tracks, enable sleep time (e.g. 5mins) and wait till phone locks and playback stops after the period.
2. Unlock your phone and try to use miniplayer or switch to the app.
3. Try to start playback again / skip tracks / load new tracks / ...

Context

App version

3.1.7 1c70d300 (2019-07-02) from fdroid

Android version

Android 9 - LineageOS 16 (discovery 2019-08-26)

Device model

Sony H3213

App mode

Smartphone