Not sure if this is it Olpal, recovering from some  VST weirdness here too. Are you scanning any folders with VST 3 plugs in it. To be sure, launch the plug in manager and click on VST 3 effects. If there are any there, chances are you won't find the VST 2.  If you need to exclude any of the folders with the VST 3 the location of the VST 3 dll should be displayed at the bottom of the plug in manager. If you exclude the folder and rescan, it may work. It has for me for the projects I need to work in X2.
 
FWIW, the default location that Cosmos wanted to install here was C:/ Program files/ Steinberg... I changed that to C:/ Program Files/ Cakewalk/ Vst.... and all woks well here. Hope you get it sorted   

We've tried uninstalling/reinstalling them in both folders. We've rescanned eleventy jillion times. Rebooted many times as well.

Sonar sees them...scans them...but won't show them in plugin manager...even as excluded plugs.

The dll files are there in the correct folders.

All other vsts are working fine.

I hate not being able to fix this.

Sheesh.