Does this work any better? https://www.aa.com/homePage.do

Unfortunately no. That is the address I have been using.

Maybe it's a DNS problem. DNS is the system that converts host names like www.example.com to server IP addresses. If American Airlines has been changing its infrastructure or hosting, perhaps your Firefox is using the wrong IP address.

Are you using DNS over HTTPS? This is a feature to bypass the DNS server specified in your Windows settings so your site lookups are private from your ISP. It is allowing me to get to the site, but it would be useful to know whether it is causing a problem for you. Here's where you can check:

• Windows: "3-bar" menu button (or Tools menu) > Settings (previously "Options")
• Mac: "3-bar" menu button (or Firefox menu) > Preferences
• Linux: "3-bar" menu button (or Edit menu) > Preferences
• Any system: type or paste about:preferences into the address bar and press Enter/Return to load it

In the search box at the top of the page, type dns and Firefox should filter to the "Settings" button, which you can click.

I think Firefox normally turns on DNS over HTTPS with the provider Cloudflare. Do you have that? Any difference if you switch it (on or off, as the case may be)?

Oh, you might need to clear old DNS lookups from the cache. To do that, you can paste the following internal address to the address bar and press Enter to load it:

about:networking#dns

If AA is listed, click the Clear DNS Cache button.

Okay, now, any difference?

Actually, you are getting to the site, but not able to log in? Perhaps your cookie policy is too restrictive, for example, using the Strict level of Tracking Protection. More tips on cookie policy in the following article: Websites say cookies are blocked - Unblock them.

Thank you jscher2000 for the suggestions. I tried each one with no success. I switched the provider from Cloudflare to nextdns and tried the various proxy settings. I also cleared the DNS cache. I am using the standard cookie setting in Firefox. I cleared all the aa.com cookies. This issue is only happening with aa.com. Other travel sites are working with my login. I might try deleting Firefox and reloading it. Thanks again.

If you want to test without any of your current settings, add-ons, or accumulated data:

New Profile Test

This takes about 3 minutes, plus the time to test your problem site(s).

Inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it.

Take a quick glance at the page and make a mental note of which Profile has this notation: This is the profile in use and it cannot be deleted. That is your current default profile.

Click the "Create a New Profile" button, then click Next. Assign a name like June2021, ignore the option to relocate the profile folder, and click the Finish button.

Firefox will switch your default profile to the new one, so click the Set as Default Profile button for your regular one to avoid an unwanted surprise at your next startup.

Scroll down to June2021 and click its Launch profile in new browser button.

Firefox should open a new window that looks like a brand new, uncustomized installation. (Your existing Firefox window(s) should not be affected.) Please ignore any tabs enticing you to connect to a Sync account or to activate extensions found on your system to get a clean test.

Do the problem site(s) work any better in the new profile?

When you are done with the experiment, you can close the extra window without affecting your regular Firefox profile. (June2021 will remain available for future testing.)

Thank you jscheer200. This is working. I will experiment with the profiles and hope to get Firefox back to working normally.