Paramount +

No idea, have mine set to Auto also for the audio.

It appears that the settings are different between audio and video. The video setting on auto sets the resolution to the highest the TV can possibly handle; for my living room TV that is 1080p. For audio, it just passes through the highest format your receiver or TV can handle.

IMG_5559.jpeg
 
I know, I took the show out of my list this afternoon, really have no interest in it, but it was still in continue watching, that is why is shows in my first photo, 38 min left.
That's not the home screen though, that is after you click on the show. If you highlight the show from the keep watching row, like you did from My List, the top of the screen will show it.

I didn't check to see if it was playing in 4k or not as I have my fire cube set to upscale since it does a great job with it. Since it's Dolby Vision, I don't know why they wouldn't have it in 4k.
 

Traditional Providers Losses, 3rd Quarter 2024 Edition