The game does not always launch in HDR. If you’ve force quit the game or crashed, it will not relaunch in HDR when starting it back up. The only way to get HDR back is to restart the Xbox. I noticed a discernible difference in my brightness and my dynamic range when I started the game up after restarting my Xbox. When I mentioned this to another player, he confirmed that it’s a bug that happens to him as well.
This means if the game crashes or you have to force quit the game for any reason, you cannot get HDR without restarting the Xbox. This means your gamma calibration will not be accurate. HDR actually makes a pretty big difference on the night maps
I’ve tested other games to see if the force quit causes a loss of HDR and so far it seems to be a problem with just this game.