I had a bee farm that took me forever to get as the world i created was pre 1.15. So i had to go far far away to find a newly generated chunk. When I got back I set everything up, the bees were dandy. IDK exactly why but all of them started heading in a single direction away from the hives. I followed them for about 200 blocks when I stopped. My theory is they are moving to a 1.15 chunk versus the 1.14 chunk the hive is located in. This all happened after I placed a campfire underneath the bees to harvest combs.