Still happens on 1.21 final release. Oddly enough it only seems to happen with newly enchanted weapons. If you enchant a weapon with sharpness or something that increases the damage and then update to 1.21 from an older version, it doesn't have the bug. While if you try to enchant a weapon with something that changes damage levels in 1.21, it doesn't change the damage level.
Still happens on 1.21 final release. Oddly enough it only seems to happen with newly enchanted weapons. If you enchant a weapon with sharpness or something that increases the damage and then update to 1.21 from an older version, it doesn't have the bug. While if you try to enchant a weapon with something that changes damage levels in 1.21, it doesn't change the damage level.