There is a post on this topic in the S20 category on this forum. I have the same issue but cannot access the link below containing the discussion/resolution- I get "You do not have sufficient privileges for this resource.." when I attempt to assess the thread. So I am reposting here.
I have an S22 and had enabled Adaptive brightness since it would seen a useful feature. However, under constant lighting conditions, I will be using the phone and all of a sudden it will dim for about 5-10 seconds then restore the original brightness level. At first I thought I might be blocking the sensor, but I really don't think so.
I have shut off the Adaptive brightness feature but if there is a better fix, I would like to know.
Hey there! I can definitely understand wanting to use all the features that your device has available. That thread has a few troubleshooting steps that may help the adaptive brightness feature like making sure your phone is on the latest update as well as clearing the cache on your device by
Turn off the device. Press and hold the Volume Up key and the Bixby / Power key. When the Android logo displays, release both keys. An 'Installing system update' message may show briefly before the Android Recovery menu options appear. Press the Volume down key several times to highlight Wipe cache partition. Press Bixby / Power key to select. Press the Volume down key to highlight Yes, then press the Bixby / Power key to select. When the process is complete, Reboot system now is highlighted. Press the Bixby / Power key to restart the device.
If you've already attempted troubleshooting for this I would suggest submitting an error report by going to the Samsung Members app > Get help > Send feedback > Error reports
