W900 marker lights wont flash

Hopefully, someone might be able to help with this, I've got a 2022 W900 and for some reason when I hit the interrupt button on the smartwheel my cab lights won't flash anymore the trailer lights do but not the cab lights. I took it to Kenworth and they replaced the smartwheel control module but it's still doing the same thing. Kenworth told me that the cab lights never flashed which is baloney. I can hear the relay clicking and checked all my fuses but still nothing. I'm hooked up to the same trailers all the time and everything worked fine for the first two months. Anyway I'm hoping someone might be able to point me in the right direction as to where to look next...

 

Oh ya for sure I will, I was just hoping it would be an easy fix and save myself a trip to the Dealership and avoid the downtime... I'm not done with Kenworth yet, and your right I did pay a pretty penny for it...