I’ve used multiple Chromium based browsers, and they all don’t work, sometimes they do.
What I do, is I clear cookies, login via Google again, do my 2FA and then the page loads, If I where to close the page, open it again I would have to clear my cookies again since I would be in a endless load loop.
Even as of now (for me) the clearing cookies don’t work anymore and I have to use a different browser.
It is a pain in the ass, since Brave can’t do anything about it and OpenAI is lazy or something.
Just use firefox (Even with FireFox I someimes have issues but rarely)