Huh that's strange...
For me it resets any blocks in a room whenever I leave it so that never happened in my run.
So maybe it didn't clear the rooms properly for you?
A: you missunderstood me.
Step 1: place a block inside of a door
Step 2: go into the door
Step 3: automatically walk into the block forever
B: it seems like it got fixed.
Yeahh tried doing what you said, looks like it got fixed. Looks like it treats doors like regular walls now so you can't place blocks in them.