Steps to reproduce the issue

Go to the Backend > Global Configuration > Server > Database Settings
Try to use a different DB (Example: a DB of a empty Joomla installation).
You can't specify the DB password (in FTP configuration you can)

Expected result

Actual result

Additional comments

On save Joomla must check if the new connection parameters work correctly (like in the installation setup) and the save the info.
The issue is for J3 and J4.

I think without the password the other DB fields is pointless.