It can also happen if you're facing a team with QGJ, if he's just used HB to grant the AI team offence up and you try to dispel that then it might not work. This is a problem that I've been having for the past couple weeks now yet never had an issue with this before, and even now it doesn't happen all the time and sometimes I get the buff but more often than I'd like, it fails. And before anyone says, no it wasn't dodged because Rey still took a heap of damage and lost the buff, and the game even tells you when something is resisted/dodged/deflected and that did not occur so clearly there is some issue with it not working, it's supposed to dispel buffs and grant offence up that's what the moves description says so if they're gonna pick and choose what buffs this and does and doesn't work on then the devs need to make that clear in game because this is ridiculous. It never fails when used against me, it's even gotten rid of defence up in the past and given the team the buff which has never worked for me