macOS using Windows 2003 shared print queues

Hi All, hopefully someone on here has an idea!

I have a small school where staff are using MacBooks, but their internal network shares are located on an old Windows Server 2003 Standard Edition box. When a user attempts to connect with the shared print queues and is required to authenticate, they are refused with an incorrect password error of the shaking dialog box.

The server has all the required services turned on/enable & disabled, but I continue to get this error.

Any thoughts or ideas would be greatly appreciated.