How to fix skin bug
you have to switch to another champion then switch back to the champion and reselect the skin. thats how i fixed the glitch on team builder, and you have to keep doing it whenever you enter the teambuilder lobby.
like for example
i have rumble + skin currently on the teambuilder lobby from last game switch to a random champion switch back to rumble (he should have his normal skin selected) then switch back to the skin i was using
and this should fix the problem everytime, probably works in normals to