After reading through this topic I somehow got the impression although the player is often recommended it still seems buggy.
Have you tried another player just to verify the simple playback functionality e.g. MXPlayer / VLC which work pretty well for me via BT earplugs.
In some cases there may be a delay when using BT audio. MXPlayer has different routines to handle this.
Maybe you have some kind of runtime delay causing the crash. Have you tried to use Vanilla… without BT active (using headphones via the conventional audio jack if available) just to see if it crashes anyway after some time?
Have you tried without active wifi?
and here
I am just guessing.