And, speaking of general. What kind of information would be helpful?

With Edge and Chrome, gmail downloads quickly. I'm able to move around the inbox and other boxes to delete, search, respond and create emails.

The problem with Firefox is more than slow downloads. My whole use of gmail is like swimming through molasses. Eventually, an email will open. Eventually, a search will find what I've asked for. Eventually, the "Compose" button will produce a fresh item.

This could be a problem with the TLS 1.3 Early Data feature also known as Zero Round Trip Time Resumption (0rtt). You can try to set security.tls.enable_0rtt_data = false on the about:config page to disable this feature until this is fixed by Google or Mozilla to see if that helps.

See also:

• /questions/1376015 Issue with most Google sites on Firefox v100 64bit