Summary:

Tridents thrown by drowned at the Axolotls become stuck and just remain in place, spinning forever.

Details:
I have built a drowned mob farm with columns of bubbles to push the drowned (and sometimes squids too) up to a top row with some current, which pushes them over and off a cliff. This was built quite a while back. With the recent introduction of Axolotls, the drowned that spawn with tridents now attack the Axolotls that spawn in there. Now, when I go to look, there's sometimes a whole bunch of tridents that are just madly spinning in air.

Screenshots:

The two screenshots are from the same position, in spectator mode, but pointed at different parts of the current section of the farm. One is with night vision, the other without. Both show a collection of tridents spinning in mid air.