If you are correct and "everything is the same but the result is different" then the only possible conclusion is that you used Chrome to setup the 2 that fail and literally any other web browser when you made the first one.
Chrome does not play well with Xerox or FujiXerox printers, password fields do not update, which in turn means a login failure.
If it isn't the browser, then the format of the user is incorrect (Windows 10 is never just a username, it is always domain\user, hostname\user or user@domain) You can get the proper format straight from the share folder (Use it exactly as it appears in the brackets) and it goes without question it should have full control.
I have 3 computer all on Windows 10 only one won't accept a scan from the machine. They are set up identically. I keep getting username or password is incorrect. I have created a new local account gave access to the shared folder logged on to verify password but to no avail. I am stumped. Am I missing a setting or something?