I played two games recently on The Scheldt map and both had odd stuff happen. I was playing PE Lufwaffe with one normal and one expert ally against 3 expert Soviet AI's. both games crashed before finishing so I have no replays.
The first game I had a squad of G43's in the building adjacent to the foot bridge which I had upgraded to a field station. The building got hit by what I presume was a molotov as it started burning. I ordered the squad to exit the building and waited for it to finish burning before re-entering. The burning lasted what must have been a good 2 or 3 minutes, and afterward none of my infantry could enter the building anymore. The mouse icon simply didn't change. They were still healed by standing near the building but could no longer enter it.
The second game was nearly identical except that after the molotov had finished burning, the squad could enter the building but were no longer healed by it and nor were any other units nearby.
I think naval infantry nearby were the only common thing in both cases but I can't be sure (no replays
)