When walking in a woodland mansion after a while you will hear footsteps coming from the above. when you break the ceiling you will find out that vindicators spotted you even though you are on a different floor from them.

Steps to repeat this issue:

1. Walk into a woodland mansion.
2. Be in survival mode.
3. Keep walking around in the mansion until you hear footsteps above you.
4. Break the ceiling.
5. You should be greeted by vindicators that have been following you.

What I expected to happen:

The floor above should have vindicators in their expected spots and not be waiting for you when you go to the 2nd floor. They can see you through the floor. and that makes it so that when you go to the next floor a horde of vindicators will attack you.