As SkypeforLinux has no NDI support, I decided to split the work between two computers. A windows laptop to manage Skype videochatting with NDI support and a Archlinux PC with OBS and the obs-ndi plugin.
Both computers are wired to the same LAN. I have tried it with a third Windows Laptop with OBS installed, and it finds de ndi sources (form the other laptop Skype) without problems.
But when I try it with the Archlinux PC (no errors of any kind in the log, ndi initialized succesfully), no ndi sources are available in Source Name.