glibc, or the GNU C Library, has recently been updated to 2.36. While this release does contain quite a few bug fixes, it’s also created others. For gamers in particular, it appears that this update has caused a regression with games that use Easy Anti-Cheat (EAC). That means MultiVersus, Elden Ring, Apex Legends, and any other game that uses EAC (depending on the version being used) will no longer work on Deck or on Linux via Proton.