@MojangSupport I migrated my account recently and now the launcher and the website says I don't own the game. I contacted Minecraft Support, who told me to contact Microsoft Support, who told me to contact Xbox support, who just sent me back to migration faq. Help!

This usually means you're logged in to the wrong account. Please try logging in with any other emails you might have used to migrate. Try the email previously on your Mojang account, or the Microsoft account you were most recently logged into. ^NS

I have tried all this. I can still log into my account, and I could play on this account for a few months until now. I have tried my Mojang login too; it says account has already been migrated. I'm using the same email for my Microsoft account as my Mojang one had.