I am having issues logging into all my Trial sites (and live sites actually). This is an issue across multiple browsers too. I have tried dumping my cache but it doesn’t fix it. Just keeps refreshing back to login again or it hangs. It often takes 2, 3 or 4 goes to get into the website admin.
This has been reported and a fix is coming.
But a hard refresh on the login screen should allow you to login straight after.