https://mhnu-my.sharepoint.com/:i:/g/personal/sander_machulp_nu/EQb_VLOXLuhHnl9cg0W3GcIB8A0x0A8-sNqiEjXJ0IEsLw?e=2PBmif

You are talking about the input box under; e-mail? This could be the Password Manager. It might also be the Form Filler built into the browser. Password Type '''about:preferences#security'''<enter> in the address box. Look under '''Logins, ''' Note: For Firefox v56+ its; '''about:preferences#privacy''' Look under '''Forms & Passwords ''' Or type '''about:logins'''<enter> in the address box. +++++++++++++++++++++++++++++++ Turn on '''Remember Logins. ''' To check the passwords you have listed, press '''Saved Logins. ''' Press the '''Exceptions''' button and see what's inside. https://support.mozilla.org/en-US/kb/password-manager-remember-delete-edit-logins ------------- https://support.mozilla.org/en-US/kb/automatically-fill-address-and-credit-cards https://support.mozilla.org/en-US/kb/control-whether-firefox-automatically-fills-forms That could be the form filler built into Firefox. Click in the field, enter a character or two and STOP ! Using the arrow keys, highlight an unwanted entry. Then press '''Shift + Delete''' Repeat as needed.