Mod menu and other mods not working

I was trying to play in a server with mods and for some reason the mods didn't work, I checked and they were the correct version and everything. The last time I played with mods was a week ago in a different server with different mods and those worked too, mod menu included. The past server was 1.20.1 and the current one I' playing on is 1.21.10, any idea on what is causing the problem or if I'm missing something?