Self adjusters keep overtighten

I know you said everything is new Are the drums? If everything else is good, and you are using old drums my thought is to swap the drums side to side and see if the problem follows the drum. If the drum diameter is over the max with the way the brakes adjust it could be allowing the adjuster to "overcompensate" on the adjustment.

Here is a good article on how they operate

Drum Brake Self Adjusters: Understanding These Ancient Devices