@rvdborgt Any ideas?

That is strange. So you say the journey was added to the pass with the yellow slider, but it doesn't appear on the pass? I've never heard that before.

1. Check for updates. App version should be 24.2.0 (Check under More, scroll to the bottom).
2. Restart your app.
3. Restart your phone.
4. Do you have iPhone or Android? Which version of the operating system?
5. If nothing helps, go to More > Settings, scroll to the bottom and enable error logging.
6. Create a new request for customer service here:
   https://eurail.zendesk.com/hc/en-001/requests/new
   Include al details, also screenshots of My Trip (showing the journey with the yellow switch) and My Pass (showing the missing trains).
7. Also send your device ID to customer service, see:
   https://eurail.zendesk.com/hc/en-001/articles/4571649483165-Contacting-us-about-an-issue-

Yes it is odd. I have a iPhone. Should be a quit recent version of the app since I added it only two weeks ago, didn't check though. Restarted everything that can be restarted and redid everything that kan be redone.  The problem keeps reappearing. However ticket control on the train that wouldn't be added checkt the ticket and didn't appose

Have you added any trips manually?

@Johannes Barth 

Nope not today, when I did it worked however.

Have you added trips manually previously? 

There has been a bug that made journeys dissappear on IPhones if you added trips manually. 

Try to enable flight mode or switch off the connection to Internet. I have heard that the app might work better off-line if the connection to Internet is weak.