I sincerely apologize; we did catch that issue in beta-testing and thought we addressed it, but looks like we didn't quite get it resolved in the final build! We will release an updated build in a week or so in case there are any other issues that arise (so we can fix them all at the same time).
In the meantime, please start Vasily's route during Weekend 1 in order to be on sequence with Ogata's route and doing the dentist visit during Weekend 2. This should resolve the issue as a stopgap until the new update releases (although you may have to start over/go back a few saves...).
Thank you for your patience and kind words! We very much appreciate folks reporting bugs like this!!! :D