[Snake]

I hope I can describe the how-to right enough, for this I'll call the correct 'working as intended' as "Darkness", which should always be active while not in BDPs (I think?):

- Get in a party, go inside a Player House that has "Darkness" active.
- Have the leader walk to another floor of this Player House (through Extra Level).
- If this new floor has different "Darkness", the party leader's "Darkness" will be updated accordingly to whatever settings there is, but the rest of the party members will not.

This is replicated more reliably when walking through a tile that modifies your "Darkness" values. The invisible trigger tiles.

It's expected to affect all of your party, but it only affects the leader, not the rest of the party members. It kind of forces the party members to leave the party so they can walk through this tile to get their Darkness settings updated.

In regards to the Water Houses, the ones where you go to treat water and stuff, it may do the same. At the very least it did back when.