I tried what you recommended and it seems to still not be working on Steam. The game has been uninstalled, cache cleared, and then reinstalled many times on different laptops with completely new characters/save files but no matter how long I left it uninstalled, it still wouldn't work (i even tried waiting 10 days to see if it would work, but it didn't).
I'm afraid that my steam version may just be completely broken and will never let me access the 4th step. The elusiveness of the final step and just the fact that the game is so well done is going bring me to play it on itch so i can finally experience the game fully.
Thank you so much for your help and I very much look forward to completing the full story.