I have decided to switch my external Player to Windows Media Player. I find that the quality is better than MPC-HC. Also had issues with MPC-HC not loading correct language and loading subtitles. Settings don't appear to work. Tried changing several times. LAV settings options in MPC-HC are not the same as LAV settings if I install independently.
I seem to recall that in the WMC configurator underneath Player path, you have to put arguments in such as fullscreen. And close player after player ends. I think those were the relevant ones.
Does anyone remember what the arguments are please?