Fishing rod copy bug

If the item in slot 1 and the fishing rod in slot 3 are used alternately using the keyboard
There is a bug that the item in slot 1 turns into a fishing rod.
It's a pvp technology using a fishing rod, but I'm struggling with pvp because of this bug.
(This bug can be used to copy the fishing rod infinitely.)
I'd appreciate it if you could fix this bug