I add next weapon to slot 4 and checklis "USE SPELL IN SLOT" [4] MP [26] <- not important.
LOL. My weapon change (swap) automatic for any second (maybe 2s like you said mindee). Every 2s swap if i attack a monster...
I dont know its a bug or not, but its funny.

info : slot 0 -> hok
slot 4 -> goe
and now i know why if i online via Mindee-BOT, sometimes i lose my pluid.
