Despite already being signed in and previously already having a username, it's asking me to make a new username when I attempt to launch java edition. When I put my username in, it says it's already taken. I went to minecraft.net to get this fixed and it turns out I was still logged in but it didn't work at all.
Hi there!
Can you please, log out of the Launcher and then sign in again?
You might restart the Launcher in between signouts
This ticket will automatically reopen when you reply.