We are currently aware of an issue some players are having with logins https://trello.com/c/EOs87aMY/580-unable-to-login-using-xbox-live-or-switch-login-icons Can you try the workaround included in the Trello?
This thread was added on April 02, 2019, with posts from FreightTrainUSA.
Original Post
https://i.redd.it/5cus7y4sqwp21.jpg
I couldn’t get the trellis to work
Work Around The workaround is to login to epicgames.com using your Xbox live or switch account. That will force you to upgrade your account. You will then have to use email and password as a login option