Language stats inconsistent between File Info Dashboard and filtered Table View

I am trying to assemble Development Codebase Statistics by Programming Language. The results from the Programming Languages pie-chart on the File Info Dashboard do not match the results from Table View. The best example is for C++.

1. For the Languages pie-chart I included "No Value Detected" and get 64.5% for C++ which is 4,167 files based on the total of 6461 files.
2. For the Table View, I first filtered on Files which returns 6461 (same as Dashboard). The Programming Language filter for C++ returns 4,798 files.

There are similar discrepancies with the No Value Detected data.

### System configuration
For bug reports, it really helps us to know:
* What OS are you running on? Windows 10
* What version of scancode-workbench are you running on? version 3.10
* What version of scancode-toolkit was used to generate the scan file? version 3.0.2