Note: this issue was fixed for most mobs in 1.17.0 or 1.17.10 (MCPE-41092). It was mentioned with respect to bees specifically on MCPE-60252 (this comment) but was not addressed in the fix applied for that report. Probably the fix for MCPE-41092 was only done for "minecraft:behavior.random_stroll". Bees use "minecraft:behavior.random_hover". See comment below for the triggering components.

Steps to reproduce

1. In a flat world, set up a repeating command block with {{/execute @e[type = bee] ~~~ setblock ~ 3 ~ concrete 3}
2. Spawn a bunch of bees at the command block.

Expected result

Bees spread out in all directions evenly.

Actual result

Bees spread out toward the northwest. In the screenshot below, pink marks pigs and yellow marks bees after just a minute or two, using the test world from MCPE-41092 modified to test bees instead of chickens. All spawned at the center block.