Deinstalled BG3 and backed up Files before to progress further ingame.
Gamefiles are intact.

Problems with crashing when loading from gameenvironment persist even after a clean reinstalling.
Loading Savegame from Menu mostly allways works fine.

So suggesting this will going to be either hardware related (recommended Requirements for Game), or some Software problem with NVidia Driver or just a Bug in BG3.
Getting closer.