I tried combining two golden Leggings with enchants together using a Anvil.
the one with complete durability and Protection IV
the other with 24 durability and Fire Protection IV
but for some reason I can't combine the two at all.
is this a glitch in the game if so I'd like to get it fixed.
it affects version 1.16.4, but I couldn't choose that version so I added it here
I don't think you can have Protection and Fire Protection on the same item at the same time. It has to be one or the other.