Been running my 1.17.1 Server for a couple days now without issues, that was, until my friends and I decided to build a Slime farm.
We quickly discovered that Slimes don't split, at all. The large slimes don't split to mediums and mediums don't split to small. Small Slimes still drop Slimeballs though.
The same thing applies to Magma cubes. Another thing my friends noticed, Pillagers don't spawn either.
However, everything functions properly in a Singleplayer world.
These two videos show the Server and Singleplayer events.
Thanks - Salty