Badnik Quicksand Oddity.
Happens in 2.2.10 as well but I figure I give it a test in the pre-release in case it occurred in there... and it does.
There's a bit of an oddity with badniks if placed on top of Quicksand FOFs, most likely Custom FOFs with the FF_QUICKSAND
flags as well. Depending on the box heights of the FOF, Badniks will either be able to move on top of the Quicksand or will be stuck in place and will not move from the spot. Here's a GIF showing the issue, which was taken with the pre-release.
Here is the test map file.
The 64 Label on the floor means that the badniks have 64 height above the actual floor. Green Marks on floor for the pits means that badniks will NOT move once they detect you while Red Marks mean that badniks WILL move once they detect you. There's also a gauge showing the Quicksand Depth as well as some texturing for measuring it.
I am unsure if objects are affected by this, though i did check out Pushable Gargoyles are they're not affected by this oddity.