Contact Customer Support and explain the situation. They might help you.

https://eurail.zendesk.com/hc/en-001

Write that you are currently travelling. 

You should have split your return journey in 2 parts in the Railplanner. One part from Sweden to a station in Denmark that the train passed after midnight and a second part from that station to your departure station in Germany. Then the inbound travel day would have been on the arrival day of the night train and you could have continued travelling in Germany. 

Here's the information given by Interrail regarding this.

https://www.interrail.eu/en/interrail-passes/interrail-mobile-pass/mobile-pass-faq/how-can-i-travel-back-home-by-night-train

Thanks for the help! We also talked to the conductor at she said it was okay for her. But it always depends on the person :)

@Mukhammad @Camilo. 

What's the current plan to fix this bug? The app should offer a choice on which date the inbound journey will be booked when you use a night train that enters your country of residence after midnight. It should not make the choice for the user. We've identified this bug over a year ago, so it's about time I'd say. If it is not going to be fixed soon, then the app should warn you and link to the page (mentioned above) where the workaround is explained.

@rvdborgt

If it's already reported previously, I'll try to remind the team about this matter. I agree that the notification linked to the page will also be a good solution to have in the App.

Thank you!