I am signing into my Mozilla account on a new computer with a clean Firefox install. I'm able to get into my account using an authorization code to my email, but Firefox Sync isn't working so no bookmarks/passwords/history/etc. I have a persistent "account disconnected" with a yellow triangle icon. Upon clicking through, I see "Please sign in to reconnect [my email address]" with a sign in button. Signing in does nothing. What's really strange is that my other Mozilla account works fine, which leads me to believe this is an account issue—except that I've synced this account across several devices already.

What do?