I’m not sure where or how to check if a particular airway / vor is in the Navigraph data, but for example this doesn’t show up in the database when I enter it into the FMC on the 787-10 : 50N122W.
No idea how the default aircraft interprets these things, but try 50N22 (ARINC 424 format) and see if it’ll accept that 
http://code7700.com/arinc_424_shorthand.htm