...cannot connect to Windows 10 machine remotely


Been troubleshooting a Win10 laptop for a few days now

I go to connect to it ; I see Win10 get busy (spinning wheel) but never connects

netstat -an | find "5938" shows my connection 'Established'

Thru process explorer I see teamview desktop start, then, stop and log an error (somewhere)

The teamviewer logs show me connect, establish AES256 session etc no issues

When I cancel because I'm getting nowhere I just see LoginFailed.

Tried disabling Firewall in Win10, no bueno. Added exception to Defender for teamviewer_desktop.exe, no bueno, uninstalled, reinstalled as admin, cleaned up Registry, uninstalled reinstalled, no bueno.

Disabled IPV6 - no bueno

Tried a Windows 10 client (as opposed to my Mac to connect to it, no bueno)

I can from the machine I am trying to connect to ; connect to other machines no worries. 

Any suggestions very welcome.