I converted 3D Analyst, Spatial Analyst, and Network Analyst extension licenses to concurrent. I authorized them on my License Server Administrator 10.6.0.
I launch ArcGIS Pro 2.2.2 and the extensions aren't greyed out, but they are listed as not available.
The tech support analyst is researching the problem.
I have had all kinds of issues with Pro licenses where I have to modify the service.txt file on the server, do installs and configs, then modify the service.text back.
This is really annoying that I have to go back to ArcMap to use 3d or spatial analyst tool.