Bug: After 2-3 hours of keeping up an Endless tile and taxi-ing players to it: the replicated tile, created when the taxi'd player leaves, will only spawn level 1 enemies.
This is the tile in the Glades of Andurin that has a stag statue between trees that, when activated, spawns Mockeries in 20 waves that progress about 30 levels from their initial level.
When me and a friend first noticed it, we thought it was maybe because we kept replicating a tile for taxi-ing, so the next day, I generated my own Endless tile and kept taxi-ing people to it until I started getting messages from other players about it generating level 1s. This took about 2-3 hours. I know for sure it was over 2, but I didn't keep good track of the minutes and I don't know exactly when the bug itself occurred, due to being the host.
It may also be worth noting that: when the bug occurs, the bugged original tile's mockeries use the normal 'red green blue gold' colors for their souls, unlike the white ones I've been seeing lately. (I don't know if the white ones are intentional, or not.)
The bugged original tile will also give normal level progression when activated, unlike the replicated tiles that will only generate level 1 enemies that do not increase in level.
Edit Dec 28th: I had someone tell me about it bugging after 2 hours, so I'm changing it from 3-4 to 2-3.