Look in nvidia control panel or geforce experience, make sure HDR is disabled.
There's 4 ways to make any setting to actually show on the screen.
1. Global settings. That's gpu direct settings which apply to All output, regardless of what's used.
2. In game settings. Apply only to that game.
3. Software settings. This includes Msi Afterburner, geforce experience etc and is temporary override global setting that applies only when active.
4. Monitor settings. Do not affect anything other than visual display, if HDR is disabled at the Global level, enabling or disabling at the monitor does nothing. If HDR is enabled at the Global level, monitor Disable cancels visual display of HDR, but doesn't affect Global output of the gpu.
In other words, you'd need to disable gpu HDR at the Global level to affect All output or disable HDR in software to affect the all output when software is active or disable HDR in game to affect only that game or disable HDR at the monitor which disables only the monitor.
Since AA is per game, HDR needs to be disabled either per game, software, or Global, as monitor is After so doesn't affect anything Prior.