Sooo.... Nami has two classic skins
This wouldn't be such a problem, but Nami has two classic skins. Selecting the Wrong one of these skins when you are a leader in teambuilder results in you having to remake the queue, and hoping that your friends will understand when you say you "Selected the wrong skin". If it would let you play after selecting a different skin, then fine, I don't care, it can stay. But as it stands, you are better off with a friend inviting you because, as a Nami main, I have a skin for her, and because of another annoying bug, I have to switch to the classic skin, and back to River Spirit. The problem is, sometimes, when switching to classic, I get "INVALID_SKIN " or something along those lines.
TL;DR: Nami has two classic skins that when selecting one of them, breaks the ability to use Team Builder