[BLOCKING LIVE CONTENT] I think follow range is broken?

Verification builds: Release 853103
Summary: In Monster Battle Arena, the mobs don't attack outside a range or 16 even when specified by behavior packs.

Repro Steps:
1. Download and start MBA
2. Press button for battle arena mode
3. go to either side of the field and summon a zombie on both sides
4. flip the lever to activate a battle

Observed Results: the mobs should cross the arena to fight each other. They will not notice each other until they are within 16 blocks of one another despite both attacking range and follow range being set to 100 in the behavior pack.

Expected Results: the mobs should be able to gain a target from across the arena, they've been successfully doing it now for 8 months of marketplace.

Videos attached: https://youtu.be/U1maDh7cyUQ