piCore Player / SAMBA & Windows 10 - Password permission denied

I have an Rpi3+ all successfully set up with a Allo Boss Dac and a USB HDD with all the music files. ( Sounds great ).
Even have it also "playing" to two Airport Express, when I want to.

Trying to get the Windows 10 PC to "see" the files on the USB HDD via SAMBA.
I have all that set up as per the piCore Player Documentation.
I can see the drive on my MacBook and successfully enter the user "tc" and the password that I set.

BUT same does not work on the Windows PC.
I have SMB check boxes ticked etc etc
I assume I have the correct path address as I get the the Enter Network Credentials for user and password.
No matter I enter the saved password - no access " The user name or password is incorrect".
Yet the same work on the MacBook ?

Any ideas for the next thing to try ?
Much appreciated,
Julian