It seems I’m having a situation with my Apple TV 4K. If I play any source in Dolby Vision for example Mandalorian through the Apple TV (Disney+), the TV will show it as an HDR signal. But when I play the same source directly through the Disney+ app on the TV (Google TV), it shows up as Dolby Vision. I also noticed that on the Apple TV under Format I do not see any Dolby settings, only HDR and SDR. The TV is a Philips 75OLED808 connected via eARC to a Samsung soundbar. I would appreciate any tips, thanks!
My bet is the hdmi input your Apple TV is plugged into does not support Dolby vision.
Check your tv and make sure the ports support Dolby vision, I’ve seen tvs that only support it on their native smart tv apps but the hdmi ports don’t support carrying the signal.