Uninstalled the Steam version and Installed the Matrix version +v1.10, then the community mod installer. All good now, mods/scenarios can be seen in "single player".
As a side note for the devs, when installing the v1.10 update, either single zip file Matrix Installer, or via de "check for updates" file downloader, I get a "missing license agreement text file error", maybe someone forgot to add it to the v1.10 update. The installation still follows it´s course but you do get that msg on start-up of the installer.
Win10 Pro(x64), i7 8700k @ 4.7Ghz, 32GB ram DDR4, EVGA GTX 1070ti 8GB, M.2 PCIe NVMe (x2) 480GB + 960GB SSD´s, LG 29' Ultrawide 21:9 monitor Logitech G13, G502, TM Warthog HOTAS, CH Pro pedals, TrackIR 5.0, Corsair Void Pro 7.1 USB.