It was an error on my part, but it should have been fixed.
That is, provided you updated the game on the 16th. If you've installed the game through the Itch app, you should have automatically received the updates. If you have a standalone version, you will not receive any updates, and therefor are stuck with this small error.
You can still get his other endings if you personally go to Settings > Character > Story > select chapter 25 and click start new route.