Tsukihime music won't loop, and other questions (JP version)

I read the Tsukihime Mirror-Moon translation before but want to go through the game in Japanese now.
I've got it installed and played it a bit, but noticed that the music doesn't loop, but looking up a Japanese lets plays on YT I know that the music is supposed to loop. Has anyone run into this problem?
Also, for whatever reason all the fade in/fade out transitions (eg.title to options menu) take about twice as long as normal, which isn't the case in that video I checked earlier. Any ideas?
I'm running windows 10, but when I boot up my old translated version it runs without the slowdowns and the music loops, I've also tried just about all the compatibility modes so I'm not really sure what the problem could be.

edit: One last thing I forgot to ask, does anyone know what the "WAVE" option does?

You could try putting the onscripter executable on the game folder and running that instead