Hello, all of a sudden this pause signs appear. Why ? 
The instrument is a piano, based on an imported XML file, thanx for an advice.
The rests are suggesting that the notes aren’t in the first up-stem voice. Try selecting all the notes on the top staff and changing their voice to Up-stem voice 1.
Thanx a lot, but why might it have changed by copying the notes form one to another bar when the first br is ok, but the copied ones arent?
Thank you!
See Why do these rests appear with slash voice? - #2 by pianoleo for a primer on how Dorico deals with rests in secondary/additional voices.
Thank you!