Blinking Screen

I am creating an assignment tracker app and I was advised to add a login/sign up screen. V0 did that, but now my screen (in the preview box) keeps blinking white and black and I can’t test it. I’ve tried everything: connecting my environment variables, deleting browser cache, changing fonts (thats what it said was the issue at first but I never specified anything specific).

Do you have an unlisted chat link we can look at?