The Alt Manager button clips with the Mods button (provided by ModMenu) when it didn't used to
Please make a list of steps to reproduce the problem (ideally from a fresh Wurst installation):
Just press tab to cycle through the buttons. it happens to me a lot
oh cool thanks, but not 100% a fix
Until it gets fixed, you can manually move it using the FancyMenu mod.
ModMenu provides an option to replace the Realms button. If you're like me and have never touched Realms, this is the option for you until this gets fixed.