The Grand 3.3 and WinRT MIDI option not sticking

Virtual instruments The Grand
1

I’ve just started using The Grand 3.3 (with Steinberg Licensing successfully enabled) standalone version for the first time, but the WinRT MIDI option doesn’t stick between runs of the program. Here’s how to reproduce:

  1. Start The Grand 3.3
  2. Click on the cog wheel for the options
  3. Enable the WinRT MIDI option and press OK
  4. Quit the program
  5. Start up the program again
  6. Click on the cog wheel for the options
  7. WinRT MIDI option is mysteriously disabled again

Have I found a bug?