I have a drive mapped to a networked Windows 11 PC that I use to share fonts between the machines. The ‘client’ PC (Windows 10) will happily see the contents of the Z: mapped drive in File Explorer and show all the fonts in Z;\Fonts. I can also install them manually from Z;\Fonts.
MainType on the client machine will allow me to select Z:\Fonts as a font folder but will not add it to the list or process any of the contents.
Does it help if you open the Font Folders dialog in MainType, and then modify the folder to enable “User Access”?
If I open the Font Folders dialog, I see it listed multiple times - I guess every time I tried adding it. So I removed them all and re-added. It has the same date stamp for Last Refresh and Added, but still doesn’t show.
I expected it to show in the ‘Groups’ area.
Yes, one time is sufficient 
Did you enable “User Access”?
Yes, the check box was enabled
Maybe a reboot will fix the issue.
If not, then maybe adding another mapped drive to the same location might help.
Rebooted, removed the mapped drive from the Font Folders dialog and then added from there - that seemed to recognize it and load the fonts. Odd. Thanks for the help!