What are the fields you are changing?

Please provide public link(s) (no password) that we can check out. No Personal Information Please !

Thanks for your reply. It's in a customer management system, so no public link. When I change a customer's name or zip code I'm asked "Would you like Firefox to save this login for mozilla.org?" After a suggestion from someone else I was able to work around the problem by clicking the drop down arrow in the popup asking "Would you like Firefox to save this login for mozilla.org?" The drop down gives the option to Never Save. What added to my problem is that FF on the computer I was originally using doesn't give the drop down menu arrow even though it's the same FF version as other computers I've tried since then.

Here is what you can do. Turn off the Save Logins option. The only time you need it is when you are adding/changing a login.

(changed my mind, I will eave this thread open and close the other)

When I do that the password/login I wanted remembered didn't stick. On most of our computers, using the drop down "Never save" works so I'll mark this as solved. Thanks for your help.

jrtml said

When I do that the password/login I wanted remembered didn't stick

Do you mean the setting is not remembered?

https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save

Note: Some software, like Advanced SystemCare with Surfing Protection, can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.