Something is wrong with my Visual Studio 2019 project configuration and I have run out of ideas to check. I have 3 native C++ shared libraries (A, B, C) that all sequentially stack on each other. B depends on A. C depends B. I then link all 3 to an executable. So the final stack looks like A->B->C->Executable. All of the libraries and executable live within the same Visual Studio solution. All of the code is mine. The solution file was generated by CMake.
I can set breakpoints and debug into A, B, and the executable just fine. I cannot step into library C because the symbol file will not load. The Modules window says it "Cannot find or open the PDB file." The search path does include the project output folder. When I manually attempt to load the autogenerated library_c.pdb file I see a pop up error stating "A matching symbol file was not found in this folder."
I have tried deleting everything and recreating the environment from scratch. I have compared all the project settings between library C and the other debuggable libraries but found no discernable differences. My internet searches all say how to manually load symbols or indicate that the error is because the symbol don't match. I have not found any that suggest how or why the autogenerated pdb would not match the corresponding lib or dll when built.
Given this situation, what would you investigate next? What could cause the generated symbol file to be mismatched?
EDIT: drescherjm suggested I double check timestamps. Windows Explorer lists the "Date modified" as being identical. However, if I right click on each file and open properties I get an interesting abnormality. The "Created" timestamp of the good working files all have a date and time (HH:MM:SS). The bad library_c.pdb lists a date with no timestamp. Instead of a timestamp it says "XX minutes ago." I'm not sure what this means but it is a difference.