Airlocks might act weird on the asteroids that you don't check for a while: even if they're opened by automation, they continue to transfer heat to nearby blocks. This happened to me three times, and it's a bit frustrating because it's hard to cool down the chamber after it happens.
I can't describe exact steps, but this seems to happen when the player is not checking the asteroid for some time. I tried to catch this bug by switching between my main asteroid and secondary with different automation states but was unable to reproduce the issue. So my best idea like it's removed from the cache or anything. This doesn't seem to happen on the asteroid I' mainly working on, but I can't say for sure that it's only happens when you don't check the asteroid for a while. I might just not pay attention to it.