I didn’t configure any other auth method.
From developer tools I can see:
414 URI Too Long
The url is the below, I shortened it, it was much longer.
http://localhost:5000/login?ReturnUrl=%2Flogin%3FReturnUrl%3D%252Flogin%253FReturnUrl%253D%25252Flogin%25253FReturnUrl%25253D%2525252Flogin%2525253FReturnUrl%2525