Printing recipient adresses on C4 envelopes in the wrong place

I want to print adresses on C4 envelopes using Libre Office.
I go from insert → envelope, take the adress from my database and insert them. However, the adress is always somewhere else in the printing preview. Both Libre Office Writer and the printing preview are set to C4 envelopes.
I tried moving the box with the adress to the right, but it’s already right on the edge, while in the preview, it’s roughly in the middle. Why is that, an how can I put the adress in the lower right corner (= more to the right)?

I made a screenshot of the printing preview, I’d be glad for any help I can get.

You might have to play with the orientation and feed settings in the Printer tab of the Envelope dialogue to find the correct ones for your printer.