Problems with subtitles

Hello everyone, I am trying to re-esemble some files that I have ripped from a dvd. The dvd in question is a release of a show and has the intro, various episodes, and outro as separate files. The main goal is to put the intro and outro at the beginning and end of each episode respectively and save them as new files. Unfortunately, the “main” episode sections have soft-coded subtitle tracks, and MKVToolNix absolutely refuses to merge these files unless I leave them out. I have tried re-ripping the files with the subtitles separately and merging the main episodes with the subtitles using MKVToolNix, but once I do that, it suddenly won’t let me merge them with the intro and outro. How do merge the files while keeping in the subtitles?

I have realized that as long as I just delay the subtitles by however many milliseconds long the intro is, it can re-sync the subtitles.