All networked computers show, but on one computer it shows "No Folder"

I have several home computers running Win10 that are networked (Cat 5 cable) and setup as the same "Workgroup". In my family room and bedroom the computers are just just for HTPC use (to serve movies and watch recorded TV stored on the Server computer). This function works. I have no issues with BEDRM computer getting movies from the Server computer.

The problem is that all of the computers see each other and I can copy files back and forth, but the computer (called BEDRM) says "No Folder" when it's opened. When I open Folders on any other computer, go to Network, all of the computers in the Workgroup are listed, then I click on BEDRM and it opens but is empty. So I can't copy a file to it across the network.

At one point the BDRM computer (and others) first had a popup box for me to enter the Name and Password of the BDRM computer for me to access BEDRM computer from network. I did this and that where I am now - I can now open the BEDRM computer from another computer but there are no folders or such shown so I can't copy anything to it.

This is what I tried:
1) I checked the Advanced Sharing settings on BEDRM and made sure it was set for Discovery and Sharing. The settings are the same on all my others computers.
2) I checked file sharing settings on the BEDRM computer for "Downloads Folder" and it has the same permissions as the other computers.
3) I did a Network Reset. That didn't help.
4) I went into the AT&T DSL Router settings and assigned the computers fixed addresses. No change.

The BDRM computer is a new Win10 installation (upgraded from Win7 last weekend) and that's when the problem started. I used the same Computer and User names, and Password from the Win7 OS on the new Win10 install. Maybe this is what caused the problem.

What else can I do?