have any SUV with this type of rearview mirror and honestly IMO it is the best driver assistive technological in a decade, in actual mirror mode I get a small view around 400 x 400 mm but in camera mode I get a full unobstructed view. I get the complaint about VR sickness as I had a few existential crisis’s when the vehicle was new but that issue passes with time and it is only an issue for people who have muscle memory that the rearview is a mirror, as this option becomes more popular younger generations won’t be affected by this.
I don’t think there is a way to disable the feature, it sounds like a bug in the Nokia. My only suggestion would to be to use the Tasker app and write an automation that automatically turns off Adaptive Brightness if it is turned on. If the brightness changes when Adaptive Brightness first turns on you could have the task restore the previous brightness also. I know this shouldn’t be needed but it is an option.