a shocking amount of modern engines/games have disfunctional framerate caps sadly.
it's especially annoying when playing something on the Steam Deck. because there your only option is using the game's own FPS lock, or SteamOS' system wide FPS lock.
and SteamOS' lock has an insane amount of input lag the moment you go below 60fps.
so if the game's lock is broken, you have 2 options. stutter or input lag... yay...
so in the end I usually just let games run unlocked with the Deck set to 90hz/fps
Amen brother! It can't be said enough that nitpicking on the net is such a minority and a very large portion of players simply don't care about such things when all versions look so good.