Looking to Remove Buff - Bug?

[PokerFace-KT]

A few players in my Legion seem to be having this common issue;

Item Drop Rate Boost - 10% chance increase. (72 hours.)

Usually these sorts of boosts are able to be removed but for some reason, this one can't, even after right clicking on them . My Legion members want to be able to get the Halloween Buff - but they can't, because this buff is in it's place and both can't be on at the same time. They just want it to be removed so that they can get the Halloween Event Buff.

Any help with this issue would be great! Thank you.