Sorry, no idea. https://pcgamingwiki.com/wiki/Home (a very good website for helping to get PC games properly patched and working) doesn't list the game, and Scummvm doesn't support the game.

You could maybe try running the game in Windows 95 on a virtual machine on your PC, but I can't advise you on that. If the problem is due to the game being run on Windows XP or later, when in fact the game only fully works properly on Windows 95, then that would probably allow you to play the game correctly. But it does seem unlikely to me (though I'm no expert at all, so I might well be wrong) that an operating system incompatibility issue would only effect one quest line in the game. Still, there are some really knowledgable people on here who can advice you on setting up and using a virtual machine (which you can then use to play other games that don't work well with more modern operating systems), if you don't find a different fix for the game's problem.