A friend set up a minecraft server recently, like in the last couple of days. Needs my username to white list. I gave them my microsoft username. No dice But

A friend set up a minecraft server recently, like in the last couple of days. Needs my username to white list. I gave them my microsoft username. No dice But the old mojang one works. So I don't know if that means I won't be able to play on my friends server come march. Single sign-on is best when it's an alternative, not the only way.