LAV splitter not launching for unknown extension causing issues in MPC-HC

Hi, I had a weird problem where if I was playing an incompletely downloaded file in MPC-HC (where the downloader would add an extension after the actual file type), MPC-HC was listing the audio tracks in the subtitles menu and the audio menu had just one track with a generic name. MPC-HC switched the audio track when choosing an option from the incorrect subtitles menu and it was impossible to change subtitle tracks. I tracked down the problem to this happening to any file (fully downloaded or not) where the extension was not a standard video file extension and noticed LAV splitter was not running during playback in those cases (which is likely related).

This forum seems to be the only place to report issues in MPC-HC hence posting here for help, thanks for any assistance possible on this one. I rely on MPC-HC to check files as they download and this problem hinders those efforts.

This means another splitter was used (due to a higher filter merit). Which splitter was used?

If you enable all source filters in the Internal Filters section of MPC-HC options, then it should use LAV for everything.

How can I determine the splitter? I can't see any icon in the taskbar when this issue happens to provide an indication and would prefer to ascertain that before manually overriding settings from within MPC that might prevent diagnosis.

You can which filters the player uses here:
MPC-HC menu > Play > Filters

And you can get a list of all installed filters this way:
Codec Tweak Tool > Generate Log