Special K seems to be unable to maintain control over the tearline in Elden Ring (among other games).
Adjusting the sync offset in an effort to move it offscreen results in jumping to a random spot with every adjustment. Any resync - whether automatic or manual - does the same. The same applies to adjusting anti-roll rate. Also, toggling “Allow Tearing” seems to do nothing.
I’ve encountered this same issue in Dark Souls Remastered, the OOT pc port and GTA San Andreas, but interestingly enough I found a way to fix it in the case of GTA SA.
Toggling the game’s frame limiter fixes the issue and allows Latent Sync to function as intended.