I have a fairly standard honey/honeycomb farm which has worked in both 1.16.5 and 1.17 up until recently. However, all 24 bees in the enclosure disappeared.

The bee habitat is fully enclosed with glass, stone, hoppers, dirt, with all 8 beehives facing forward. There are several solid blocks above the bees. (See screenshot 1)

Confirmed absense of bees by listening for standard bee noises, waiting a full day, and confirming that hives are now empty by breaking a few and seeing that they stack. (See hotbar in screenshot 2)

Update info:

World seed: 6937737252489211091

Coordinates: 290, 67, -86