This was also happening to me so I did some experiments and might have found out why. If two bees try to enter the same hive with already two bees inside, the one that is left outside might wander off for no reason. I made a bug report about it here if you want some more info.
This was also happening to me so I did some experiments and might have found out why. If two bees try to enter the same hive with already two bees inside, the one that is left outside might wander off for no reason. I made a bug report about it here if you want some more info.