They removed the F05 Beta firmware, hopefully a new firmware version is incoming?
https://www.gigabyte.com/Monitor/AORUS-FO48U/support#support-dl-firmware
It is yeah, didn't even realize Windows captured that data until I started playing Deathloop (which automatically sets the peak brightness to what is detected). I've tested a couple of games (Mass Effect Legendary edition comes to mind) that have the "get the box to disappear/match" HDR...