No, it should work either way, as long as you finished the events at the onsen. Maybe you're not going far enough into the secret prison? The trigger is one tile below the spot between the two guards in the first secret prison area.
Upload it somewhere else, for example MEGA, and post the link here. (If you're on our discord server, you can send me the file there as well, without having to upload it.)
You can find the save in the www/save folder. I only need the save file with the number of the save slot, in which you have the issue.