I have been doing some tests with villagers and ladders after I saw a cleric villager spinning on the roof of the church, and found that ladders were buggy for a few mobs and not just the villager. A mob that climbs a ladder has a high chance of getting stuck at the top and just bobbing up and down making the ladder essentially unusable, and they can’t climb down or get off at any other floor. Furthermore, a villager stuck at the top has some sort of pseudo-invincibility by not being targetable for the illagers and any mobs stuck in the bob will more likely than not just bob with the villager. I’m not going to rule out the 3x3 ladder tube with 5x5 rooms attached causing any mob ai issues too, but I figured that the bug was prevalent enough in my tests to report.