Warzone has been a problem for me for ages.
Possibly I came across something that helped with, however.
I always use OBS as an admin, have GameMode on, limit the FPS and try everything once ...
I also tested the hardware accelerated GPU scheduling, since I use several monitors anyway, one of which is set to 120 Hz and the rest can only be 60 Hz.
Always had laggs with Warzone.
I tested it again today and came across that OBS does not recognize that I have switched it on.
The LOG says that it is OFF.
Then I wanted to look at the entry with regedit (HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ GraphicsDrivers) and saw that there was NO (!!!) DWORD file for it.
That was missing ...
I then created one with the name "HwSchMode" and entered 2 for Value Data.
After that, OBS recognized it and then it was really on.
I've just tested it for a round of Warzone and it looks smoother than before.
So now I've switched on GameMode and Hardware Scheduling.
I didn't notice it before because I switched it on in Windows but didn't pay attention to whether it was recognized in OBS.
It may also help one of you.
I used Google translate.