What version of smarter mail ?

I found that FireFox seems to do some of its own "whatever it wants" type of things sometimes.  Do you have autocomplete turned on in Firefox? are you using any additional ad ons for FireFox ?

I can reproduce the issue on the Smartermail build for Linux from last week, and a version of Smartermail from several years ago on a Windows server.

If you mean auto-fill (the built-in password manager), I do on one version of Firefox and not on another. In both versions the behavior is the same. However on the version with the password manager, I can at least login if I click it from the dropdown because it fills both fields simultaneously.

Yes. I tried on a fresh version of Firefox Developer Edition with no configuration changes and the login prompt works as expected.

If I turn off the Bitwarden Extension in the versions of Firefox I observed this behavior, the login prompt works as expected too. It seems Bitwarden causes this bug to occur when it modifies the Javascript on the page.

Edit: I can also reproduce this bug in Chromium-based browsers when the Bitwarden extension is installed and the vault is open.

So its a bitwarden problem and not really a smartermail problem :)

I filed a bug for the Bitwarden extension.

Bitwarden, I thought I saw that problem on here before :