Thank you for your message. I am sorry you are having this problem.
Here are some things to try from my checklist. You have done a few of these already:
Ensure you are running a supported operating system and browser. That list is located here: Technical requirements. Even if an unsupported version worked before, it might not work now.
Try restarting the browser.
Try using an alternative browser. If that works, it is likely a browser extension that is interfering. You could try to use private browsing or incognito mode in your regular browser, but some browser extensions work in those modes as well, so it is not a completely effective test. If an alternative browser works, you will then need to go through your extensions one by one to find the one that is interfering and either disable it or configure it not to interfere with Adobe sites (for example an aggressive ad blocker which blocks the Firefly web site).
If you are using a VPN, try using without a VPN.
Try an alternative network connexion. For example, if you are connected to a home network, try connecting to your phone as a wifi hotspot. This can help determine if it is a network issue.
If you are running windows, reset the windows firewall to the default configuration.
If you are running MacOS, look to see if there are any lines in the file /etc/hosts that are "adobe.com". If so, delete them. Be very careful editing this file as changing other lines can cause problems.
If you are running a Mac with Sequoia, try upgrading to the latest OS update to 15.0.1 or later.
If none of these work, please tell us the OS and browser you are using and the version numbers.