I cannot access shared folders on a private network, even from the server computer with an administrator account.
This is going on for about 2 days, and I have searched many similar issues online without any progress on solving the problem.
I will list bellow what I have found so far that seems to be the most relevant.
During troubleshooting I tried to create a new shared folder from the Server Manager and the following is happening:

However, when I create the share from the folder properties in the file explorer, the share is created, and can be seen in Server Manager.


When inspecting the properties of the shared folders the following error also occurs:

In the server computer I can see all the shared folders when opening \\servername.
When I try to open any folder, from the server or from a remote computer, the following error occurs:

I have so far checked:
- SMB1 and SMB2 is running (from powershell)
- File And Printer Sharing is allowed in firewall
- Tried opening with firewall disabled (same error)
- Tried using net use from powershell (also error)
- File And Printer Sharing is allowed in Control Panel\All Control Panel Items\Network and Sharing Center\Advanced sharing settings
- Port 139 is Listening (tested from server and remote)
- Port 445 is NOT Listening (server and remote), but is allowed in firewall
I have found also two odd issues. The FIle And Printer Sharing is not showing the NIC properties, neither SMB feature in the server Manager:

I hope to not have to reinstall the server to fix the problem.
Any help is appreciated.