Visual Studio 2022 File not found in current source file's directory or in build system paths

For some reason, the Calculator.h is not being seen by the Visual studio, evert time I build the solution it keep throwing same error E1696 cannot open source file "Calculator.h" and C1083 Cannot open include file: 'Calculator.h': No such file or directory.

I tried to clean and rebuild the solution, that as well didn't work. But in same directory main.cpp was able to see and reach Application.h file. I tried to 'Add existing items' option as well, that also did not work.

What would be the possible cause of this? PFB file structure.

Solution Directory: enter image description here

All files: enter image description here

File explorer: enter image description here

Code where file is included: enter image description here

Here it is not being detected: enter image description here

You have some apparent duplicates which seems to be shortcuts. I'd suggest to delete the shortcuts from your project.