Loudness change

Hi there,

I am running Sonarworks Reference 4 on my Mac with an RME Babyface. When I start Cubase 10.5, the volume of my output drops. This is not really a problem BUT when I close Cubase again, my volume all of a sudden increases tremendously. So, when I play something in the background on f.e. Spotify, my ears get a shock and sometimes I'm worried I even damage my speakers.
Did anyone ever have this issue and can help?

Thanks,
Dennis