Windows 10 Can't create a working file share, windows 10 pro

Hi Mark,
It sounds like you've done a lot of troubleshooting already without success. Let's go through some more steps to try and find a solution for your file sharing issue.
First, make sure both computers are on the same workgroup. To check this, right-click on the Windows start button and select System. Under the Computer name, domain, and workgroup settings section, click on Change settings. In the System Properties window that opens, click on the Change button next to Workgroup and make sure both computers are on the same workgroup name. Click OK and restart your computers.
Next, create a new folder and share it to see if that works. Right-click on a folder and select Properties. Go to the Sharing tab and click on the Share button. From the drop-down menu, select Everyone and click Add. Set the permission level to Read/Write and click Share. Now go to the other computer and see if you can access the shared folder.
If that doesn't work, check your network discovery settings. Go to Control Panel > Network and Sharing Center > Change advanced sharing settings. Make sure that network discovery is turned on and file and printer sharing is enabled.
Finally, double-check the firewall settings on both computers. Go to Control Panel > System and Security > Windows Defender Firewall > Allow an app or feature through Windows Defender Firewall. Make sure that File and Printer sharing is enabled for both private and public networks.
Hopefully, one of these steps will resolve your file sharing issue. Let me know if you have any further questions or if any of these steps worked for you.
Best regards,
[Your Name]