No can't be moved to DB, because Interrail sells reservations for trains in Europe with optional reservations via Belgiums Railways booking system (the price 6€ + 2€).
Next time book directly via DB App to get it there (and cost less). The price is 4,90€ per journey, instead of 6+2 per train via Interrail.eu
I don't think there's a way to transfer them to the app (there's no need to anyway) but someone else may correct me.
German seat reservations are best done on bahn.com directly (way cheaper) : 4.90€ per journey (incl. multiple trains) and no booking fee. For a single train it's best to use tickets.oebb.at (3€).
Optional seat reservation prices can vary massively as you can see.