That's a WSUS issue, not a Patch Manager issue. Try this fix.
Windows 10 on WSUS Shows as Windows Vista | Title (Required):
I noticed a thread on a forum regarding Windows 10 reporting to WSUS as Windows Vista. This was a problem if you recall for Windows 8 and Server 2012 simply reporting as Windows 6.3 or similar.
Since WSUS received no updates that i was aware of to fix that issue at the time, i found a SQL Command here that updated the WSUS DB to reflect the correct OS name.
Revisiting that now, It was easy enough to modify this to have WSUS report a Windows 10 machine, as Windows 10!
SET [OSDescription] = 'Windows 10'
WHERE [OSMajorVersion] = '10'
AND [OSMinorVersion] = '0'
AND [OldProductType] <> '1'
AND ([OSDescription] <> 'Windows 10' or [OSDescription] IS NULL)
Funny you would have thought that WSUS would have had an update on or just before the release of Windows 10 to the wild -- even though most of the release was for home users .........
Nope, Microsoft is @ss backwards. They didn't even release RSAT tools for Windows 10 yet. Until they do so I cannot update my workstation because using remote server administration tools with runas is far easier than multiple RDP sessions or vSphere client sessions to servers.