[2020] F**ck this!

From the sounds of it, your CPU is falling behind what the game is calling for, and the spawning director is having to take shortcuts in zed placement- Which is to say, it's spawning them wherever it can in spite of having to break rules like 'dont spawn on top of the player' and 'dont spawn where the player can see' to do so.

Suggest taking it slower when entering larger buildings to give the game a chance to, yknow, spawn things.