I have the same problem, but apparently the error is not in the mapper. My world also "freezes" and I can't do anything in my world, on a significant beta everything works as it should. I have not found the reason for this error, but it seems to be some kind of block like a stove, a chest. I apologize if there are errors, translated from a translator.
Same error
I noticed this problem a long time ago, around 1.20, this parameter simply stopped working, I found on the Internet that mojang removed this parameter, but Iām not sure if this is true.