Recently there was a thing where VAC would erroneously flag AMD’s antilag+ feature as cheating, and issue a ban.
AMD then quickly disabled the feature by default but now Valve also patched detection for it and is now, at least according to these patch notes, reversing the bans.
Yeah it’s pretty basic tbh I honestly wish that the old school stuff like doom, unreal or quake 3 got more air time, much more potential mods and additional dynamics to add to the fun