Glad to see they are working on this issue. I too have the same issue with my 2021 bighorn 3500. Drives me nutsUPDATE #2:
We've found the issue. Albeit won't be repaired for some time, we at least know where the problem lies.
After taking the truck to multiple dealerships for repairs, it seems that this is a software issue. Dealer technicians spoke with FCA and they've identified the problem to the BCM software.
I am far from being the only one affected by this. Seems that a large batch of 2021 models in Canada have this issue. At the last dealership I visited, the salesperson checked to see if the problem existed on new trucks on his lot. Several new trucks were found to have the same problem, but not all of them. Considering the number of afflicted trucks, I certainly hope that it will put pressure on FCA to come up with a fix sooner rather than later.
I hope that this update will be able to help others that may be in the same position as me.