Thanks for your fast reply. The installation is complete clean, so I'm sure there is nowhere else the NGSolve and I double checked that there are not any false environment variables.
Find attached the CMakeCache.txt. To produce this I only changed the CMakeLists.txt to give the find_package function a hint to the ngsolve CMake file:
Code:
HINTS /Users/username/opt/anaconda3/pkgs/ngsolve-6.2.1909-py37_91/lib/cmake/ngsolve
So, perhaps you have set up environment variables that I don't have?