Can you make sure the DLLs are 32 bit:
C:\libs\fftw\3.3.5>dumpbin /headers libfftw3-3.dll | findstr machine
14C machine (x86)
32 bit word machine
And create the .lib from a x86 Native Tools Command Prompt for VS 2019
FYI the PATH has nothing to do with the build, it’s only used to find DLLs when running. (building looks for the libs and don’t use the PATH)
No, everything must work in 32 bit (I build with FFTW since ages)
No, there should be no difference.
Now can you run from a x86 Native Tools Command Prompt for VS 2019, and not in PowerShell, just to make sure?