In Easy Steel's Neoforge ver 1.21.1, Tin seems to be bugged. While tin ingots exist, they can't be used to make bronze ingots, as they are apparently missing something in its name. And by extension, Bronze Ingots can't be used in Epic Knight's bronze gear, since those ingots are also missing something that fails to have it be recognized as bronze.

This was not an issue in 1.20 and older. I don't know if this mod has been discontinued or not.