Got it sorted.
Isolated the entire rest of the network other than the server and my router/modem.
No switches, no UPS, no access points, etc.
Didn't help.
So I could only assume it was something wrong with my settings in Unraid.
It was.
Turns out I overlooked the SMB default setting as "Active Directory" instead of "Workgroup"
As soon as I changed it, presto.
So everyone have a laugh at me, I can take it.
Thanks so much for everyone that has contributed to this thread.
Anyone else that reads this...
<b> Check that you've changed from Active Directory to Workgroup!! </b>
Thanks Guys.
Also, how do I go about requesting another trial?
Burnt 3 out of 4 weeks chasing my tail because I'm an idiot.
Thanks again!