its not about the garbage room. I tore down something which generated gabage and that garbage happens to be at the doorway.

It looks like garbage at the doorway breaks pathfinding. A ton of workers and others stuck at the door and jobs near the door cannot complete. To make it worse lock the door shut when there is garbage blocking it.

Is this ever going to get fixed?

It doesn't seem like things has changed fundamentally from version 1. 1st Campaign 500 prisoners with 2 land expansion, AI starts to break. NPCs getting stuck at doors or running around not doing anything... I would say stay under 400 prisoners to make sure the game is playable