Some users experienced these issues previously, but we were able to resolve them. Please try the following steps to see if they help:
Clear your browser's cache and cookies or
Try using a different browser.
If the issue persists, please refer to this link and share the .HAR files with us so we can investigate further.
Additionally, please let us know:
If you can log in and access Express using an incognito browser window or after logging out and back in on a different browser with cleared cache/cookies.
Whether you can log in and use other Adobe services, such as the Creative Cloud home page here.