is it advisable To Change To Another Group Upon Getting The Return Offer?

Hi all, my summer is with a BB back office. I already got a return offer but I have not signed yet. I want to change to another group, front office, but not IB/S&T. Is it possible to ask for a change of group for another summer within the same firm? I don't mind delay my graduation by one year as I do not really like my BO role. Will asking to change a group kill my return offer? Anyone has experience before?

Thanks everyone!