The bug
Bees will choose a flower (noted by using /data get entity ~) and will have available pathing to it, but will never go to it, and will sit there.
Nearly all bees seem to eventually come out of the nest, and sit there, never pollinating and therefore never reentering the hive/nest to make honey.
To reproduce
Place a nest
Encase it in glass
Place a floor of dirt or grass and place flower(s) down on the grass/dirt blocks.
Wait
Use /data get entity for info on pos.
Video
Linked issues
relates to 1
Attachments
Comments
More video detail: https://youtu.be/hK4ikHU-CDM
At this point the AI of every bee in all 20 cells I'm testing have failed, not a single one is pollinating nor even moving at all anymore.
It seems the problem is in that if they can't access the block location via an obstruction when they mean to, they cease trying, and remain still.
EXTREMELY IMPORTANT NOTE:
Every time i close and re open the world, all the bees regain functionality for a moment, but again, after an hour or so, half have returned to doing nothing, and after a couple more hours, not a single bee is functioning.
P.S. : this is happening every time i try to recreate it.

Hi, is this still an issue after the latest snapshot! If so, can you please upload your world save so I can test it out for myself and see what's going on? Thanks!
Hey Cory, it is indeed still an issue in 19w42a, would be glad to share the test world, was hoping to make a video on the setup though so hopefully no one steals credit c:
[media]Attached my test world as well. I just built that structure from scratch in 19w42a, spawned five bees inside of it, and waited for a few minutes. After a while, only one bee entered and left the hive, and the other four bees remained stuck.
I assume this is closely related to, if not the same issue as MC-159350.
They also don't take pollen from Tall Flowers anymore, Bees can still pathfind sometimes to these flowers but they can't take the pollen, also seems like in most cases they pahtfind only to the bottom meaning it's impossible for Bees to reach the top of a Sunflower where the pollen is suposed to be.
[media]
@unknown, that seems like a different issue, please create a new ticket for that if we don't have one already.
Done MC-164020

Thanks for your uploads! You can now delete your test world download if you don't want anybody stealing credit 😉
Done, glad to help! Thank you for working on this 😃
This makes honeycomb and honey farm broken! 😞
Glad to see a fix to it soon! 😃
Confirmed. Bees can get stuck on the flowers since they try to pollinate from too far away.