"Endless" loading screen when tabbed out

[16Bitman]

I tab out during loading screens in this game and check other stuff, since the update however, the game keeps me in a loading screen until I tab back into the game.

That way I accidently held my team hostage when I was the host and loading into a mission.

[Hack]

Casual occurrence 

Some desktop applications tend to grab memory allocations. 

For example, you started to load a mission/map, the game starts to increase its memory usage but then you tabbed out, let's say you used Google chrome, knowing that browser technically, it is a very memory hog. So what happens is the application and the game plays a tug of war or something to who gets to be prioritized on memory allocation and when the game loses that. You basically stopped trying to allocate memory to help render the mission/map. 

[16Bitman]

It has only started to happen after U26.1, not once before in the 5+ years I've been playing this game.