3.2 failing OS check on Windows 8.1

I have an installer that exits if %OSVER% is less than 11 (Vista). It correctly exits if attempt to install on Windows XP, passes and installs fine on Windows Vista, 7 and 10. Haven’t tested on Windows 8 yet, but it is failing the OS check on Windows 8.1. Why would this be?

Works on Windows 8, Version 6.2.9200, fails OS check on Windows 8.1 Version 6.3.9600.

Tested with Windows 8.1 latest updates, and %OSVER% returns the correct version. Are you using 32-bit or 64-bit?