Put the two VIN info real oem and compare the seat models to start with.
The only thought that comes to mind is the seat module: isn't there a module under the seat that splits the connection from the car to the heater/butt sensor etc? Different model/programming interfering?
https://www.realoem.com/bmw/enUS/sho...diagId=61_1220
https://www.realoem.com/bmw/enUS/sho...diagId=61_1220
Here are the two pages for the seat wiring for example for the two cars start there see if there's a different wire that may have missing pins.
I didn't find the page with the seat modules yet but you can browse the two sets and look for where there's a change in the part numbers or see if you can swap the electrical parts under the seat.
–awr–
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