Custom Map that breaks every AI - After 20 years i finally have to ask this question

so on basicly day 1 of AOE 2 (in 1999) i've created this map which has a concept i really wanna play.. however.. every AI just cannot handle it..

the AI from the original game couldn't handle it, the AI's from the 2013 version couldn't handle (including player made AI's like barbarien and etc.) and now, when i learned this game has a new AI i tried again... and again.. the AI cannot handle this map that i've made..

and after 20 years i just got to ask... why

this is the map: https://i.imgur.com/h2VZPjj.png

it's a 4 v 4 style map, the map is split in 2 by a river except in the middle.. so it becomes the center of all combat.. and the AI just doesn't attack each other.. in this version i can force my allies to attack (with the new command system)..

but then when the enemy AI in the center gets attacked the other enemy AI's still sit idle in base.. so that's just rubbish

so any1 got any idea.. why this map design breaks the AI and just makes them sit idle in base?