Arduino Mega pin 20 and 21

Last weekend a installed my arduino mega into my electrical cabinet.
Did I/O test and everything is fine except for pin 20 and 21. They don’t give me the input to home assistant. After some measuring everthing seems to be fine.
Changed it to other pins and changed the config.yaml file and now is ok.
Could it be that thes pins can’t be used like pin 0 and 1?

Hopefully someone could give me this information…