[2019] D3D Device lost Error: 0x887A0006 - HUNG Crash Freezing Singleplayer

This is a known crash with UE4 games at the moment, it can happen with both Nvidia and AMD cards, though based on the reports we see it appears to be most common with Nvidia. Unreal has an issue tracker up for it at the moment, the targetted fix is for version 4.24 which is the next version (though that's not a guarantee), if they are able to resolve it or make changes to mitigate the crash, we'll be incorporating their fixes as soon as possible.

https://issues.unrealengine.com/issue/UE-74575