I mentioned on the other thread with this issue:
One of our team found a work around/fix that can be added to an Engine Source build.
EngineFolder/Plugins/Developer/VisualStudioSourceCodeAccess/Source/VisualStudioSourceCodeAccess/Private/VisualStudioSourceCodeAccessor.cpp
Line 224 -
if (Filename == InSolutionPath)
to
FString AbsoluteSolutionPath = FPaths::ConvertRelativePathToFull(InSolutionPath);
if (Filename == InSolutionPath || Filename == AbsoluteSolutionPath)