Quote Originally Posted by Barthax View Post
This is standard "battery optimisation" on the Android platform. As "new" apps make requests for resources (RAM in particular) the OS decides whether to unload a the oldest now-unused app. If you have a strong desire for LotB to remain, you can disable the battery optimisation behaviour on a per-app basis, forcing the OS to look for other apps instead. However, don't do this for a lot of apps: if it runs into the situation where all recent apps have the battery optimisation disabled, you're back at square one where the OS ditches the "oldest" app.

The battery optimisation settings are typically in Settings > Battery but your particular Android flavour may have shoved it elsewhere.

Cheers, I'll give this a go!