Was playing on some maps, with initial launch area space restrictions, and your AI was creating Crazy numbers of T1 anti-air mobile units. These units were blocking all of your spaces between buildings and paths out of your initial launch area.
Also even after 20 minutes it was still keeping dozens perhaps 50+ T1 anti-air mobile units. Still blocking engineer and other unit movements in your base.
For base defense, does your AI evaluate static A defenses vs static B defenses (Ie different mods) vs mobile units?
Example:
build time + energy/mass cost and DPS + range of xx mobile tanks vs
BT +E/M and DPS + range of yy turrets?
Direct fire vs ballistic units (that can fire over blocking terrain)?