Both unsupported games, so I can’t give any specific hints. Halo might be an UWP (Universal Windows Platform) game even in the Steam version, but that’s just a guess. UWP games usually are protected against hooking into them.
One thing you could try is the ‘Alternative Hooking’ checkbox in the config app. Don’t forget to uncheck it again later even if that helps, it’s not better per se, and some games will fail to work with it.
If you have other programs running in the background, also checking for potential conflicts is always worth a shot. More on that in the pinned post on top of this sub forum.