Another user recently mentioned this as well. It affects sites like Google and Yahoo that use a two-stage login where the username entry field is on a different "page" than the password entry field. The password field is no longer filled automatically and you have to trigger it from the drop-down.

I don't know whether this was an intentional change, or was an existing behavior the sites discovered and are now triggering.

But I think the username field would normally be filled automatically if you only have one saved login for the site. ??

Yeah, it's very strange. It happens on sites that do not have 2 stage logins as well...If the username and password fields are on the same page..you have to click on the username field and click the username...it will then autofill the password...two stage login sites are a pain and it would be nice to have the old functionality back.

If this happens on HTTPS (green lock) pages with both fields present, check to see whether autofill has been turned off here:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful or accepting the risk.

(2) In the search box above the list, type or paste signon and pause while the list is filtered

(3) If the signon.autofillForms preference is bolded and "modified" or "user set" to false, double-click it to restore the default value of true

Note: I suggest keeping the similarly named signon.autofillForms.http preference set to its default value of false as a cue that you are on an insecure page and the login will be submitted in easily intercepted clear text.

One reason signon.autofillForms might be set to false is if you (or one of your extensions) followed a recommendation to change that setting in response to the recent news about a way that tracking sites could steal your logins: their script inserts a hidden login form into the page for your browser to autofill, and then reads out the field contents. Setting the preference to false prevents that attack because Firefox won't autofill any hidden forms, but as a result, it also won't fill in real login forms.

This does happen on https pages. signon.autofillForms is set to true, but the problem persists

These are my signon settings: https://i.imgur.com/e1R18GD.jpg

Maybe the website uses autocomplete="off" to disable filling the form automatically. Firefox doesn't obey this attribute when storing a password, but may use it to fill the username and password.

Also make sure you do not run Firefox in Private Browsing mode.

I'm not running in private browsing mode. This happens with every website I have a saved password for...I need to click the field and select my username.