Basic Auth in Fennec not working

Checklist

• I am able to reproduce the bug with the latest version here.
• I have checked and there are no existing issues - open or closed - which report the same bug.
• I have taken the time to fill in all the required details. I understand that the bug report will be dismissed otherwise.
• This issue contains only one bug.

Affected version

1.0.8

Steps to reproduce the bug

Have a password saved with username and password and specific url.

Open Fennec / Firefox Android / Mull and access site that uses basic auth.

Click on username or password field -> Nextcloud Passwords auto fill opens up

Select saved password

Site loads forever, nothing happens.

Expected behavior

No response

Actual behavior

No response

Screenshots/Screen recordings

No response

Affected Android/Custom ROM version

Android 13

Affected device model

No response

Additional information

Obviously checked the password and username to work. Also from different desktop browser versions, where this password works. No sync error, all passwords are up to date.

Start by reproducing the saved-credential autofill flow in Fennec, Firefox Android, or Mull on Android 13, as described in the issue. Trace the Android autofill and Basic Auth entry points from there; done means selecting the saved username and password lets the site finish loading instead of waiting indefinitely, with a regression check if the project provides one.