Here's an Update to everyone
I became more acquainted with mpchc and all these filters and whatnot. I followed a 10bit guide online and pretty much made a copy of what is known as the Kawaii codec pack. I'm more comfortable with working with it but I still get this persistent issue.
This is exactly how I experience the problem. I play a random mkv, works flawless (regardless 8bit or 10bit). Open the next one in a series (tried with playlist and without, makes no difference) the subtitles are missing in some areas. For example the OP has them but the rest don't, most times it's completely missing. I open a different anime that's mkv, and it works fine, if I play another episode of the same anime it messes up again. If I restart my computer it works until it feels like messing up again.
I'm about to drop mpchc, so inconsistent. And I'm not dumb with computers, all my drivers are up to date. Thanks for all the replies everyone btw. I really appreciate the help. I've been searching on for days and a lot of people have this same issue and there's no conclusive fix for it. I made sure I had autoload subtitles checked off b/c I'm using the external xy-vsfilter, I also made sure in xy to "autoload subtitles". I'm using madVR Haali and LAV filters.