The standard macOS main menu is supposed to have a "Services" submenu that gets populated by the system. We correctly have this menu in ThinLinc, but for some odd reason we lack the ">" marker to the right that indicates that this is a submenu.
This is probably a bug in our FLTK since the same issue is seen both with tlclient and vncviewer (as well as builds of tigervnc). However upstream TigerVNC builds do not have this issue.
Created attachment 991 [details]
Created attachment 992 [details]
Upstream TigerVNC menu
Created attachment 993 [details]