If you place a comparator next to a beehive, bees are still able to exit that side. This causes a problem when trying to create a honey farm and using a comparator to measure the honey level. If you create an enclosure to cover up the redstone, then bees can get trapped in the enclosure. I noticed this today. Initially I thought all the bees had disappeared but in fact they were trapped in the enclosure.
I have attached a few screenshots to demonstrate the issue. I created 4 beehives in an enclosure. One side of the enclosure has comparators facing out of the beehives. In the other side I spawned 12 bees and added flowers. After about 5 minutes most of the bees were on the side with the comparators.
I did this same test in Java 1.16.2 and I could not reproduce the issue.
I think this should be fixed because honey farms need comparators in order to measure the honey level before triggering the dispenser. And usually players would like to hide the redstone. Plus it seems like an undesired parity issue.