Until recently you could not move the pass yourself. Only Customer Support could do that. So the fact that you can move the pass once is a big improvement.

As the Railplanner app not is updated online it is better to do the planning in Excel or similar and use the timetable of the national railways. Then add the trains in the Railplanner just before boarding the train. 

Thank you for your reply, Anna.

I, however, cannot be grateful to Interrail for -finally- adding such a basic functionality. There are so many disappointments I've ran into in the last couple of weeks, making that I will never either buy a pass again or recommend others to do so. Storing app-data like My Trip online requires very, very, very limited server space and Interrail -for the amount they charge- should really upgrade their customerservice/ and functionality. 

But thank you for your answer, Anna. I will start over in a Google Doc, wasting my whole weekend on it. 

I usually use the text version of the DB planner:

https://reiseauskunft.bahn.de//bin/query.exe/dl

Or in English

https://reiseauskunft.bahn.de//bin/query.exe/el

You can copy the results in a text document easily, or in a Google doc, use a fixed width font such as courier.

I understand it's disappointing to loose all your work, but planning with the rail planner app is really a bad idea since it is unreliable.

Ah, thats a very nice tip! Thnx. Also grateful for your reply here btw, bcs its a hassle getting seperate tickets to ‘virtual’ border towns etc.