Test Navigator Not Discovering All Tests

Yeah, that doesn't really solve the problem. According to the documentation for this feature here  the default location is the build output of each test project. So that should be fine in my case since I haven't changed the build location.  Another option that I am using, according to your documentation here is to Run All Tests in a Project.  When I right click my test project and choose this option, still, only the tests that I have opened the files for will be run. For example, I have 3016 unit tests when I click "Run all Tests in Project" only 77 tests are run.  This recently just started happening.  I have never had this problem until recently. Is there some cache file i can clean out or something?