Okay, I'm find the problem and the solution too.
The AI tries dress up the NPCs to fit the location where they work and lookup in the uniforms.txt file.
The trick is the locations are listed they common calls like fast_food, or bakery, etc.
When you take over a business they registered in game as fast_food:business, bakery:business, etc.
This is where the WHERE parameter doesn't match anymore to the AI lookup and AI dress the general clotches only like the shoes.
In the uniforms.txt file all clothing types separated with an empty line and consist four line.
Pick the fast food for the example:
fast_food
fast_food, ice_cream
Uniform-Waiting-Casual_1_F, Jiwoo-Leather-Sandals_1_F
Backyard-Bbq-T-Shirt_1, Kso-Jeans_1, Bbj-Sneakers_1
The first line is the dressing set callname ( Actor.dress(fast_food) )
The second line is the location type ( WHERE == fast_food ) or same as the first if it's not dedicated to location (like 'wedding')
The third line is the predefined clothing for females, and the fourth is for males.
Within the third and the fourth line can be define more sets for variety
with semicolon ( ; )
The solution is adding the owned business type to the second line like this:
fast_food
fast_food,
fast_food:business, ice_cream,
ice_cream:business
Uniform-Waiting-Casual_1_F, Jiwoo-Leather-Sandals_1_F
(; newfemaleclothhere1, newfemaleclothhere2, ...)
Backyard-Bbq-T-Shirt_1, Kso-Jeans_1, Bbj-Sneakers_1
Thats it, but I'm did this in the attached uniforms.txt file for all rentable location (only). If you want to use you should overwrite the old one with this.
Cheers!
postscript:
I went my day to figure out how can I dress someone with the .dress() command in scenes regardless of the location (because this isn't documented properly)

This way:
Actor.dress(
clothforactorgender1, clothforactorgender2, ...clothforactorgenderX)
for example:
FemaleTestActor.dress(FG-TShirt_1_F, City-Limits-Jeans_1_F, Gym-Brat-Shoes_1_F)