Yamaha & Dante - Playback multitrack with Cubase -> NOISE


So I’m in a situation where I recorded/mixed multiple sessions on a Yamaha with Nuendo and Dante (DVS). In total 50 sessions with artists that will be broadcasted later this month.
Some of these mixes will need some extra work.
I want to mix the tracks back into the same setup which is easy to do with Nuendo and works great. No problem there!

BUT I wanted to record my fader settings with MIDI (and play it back if I need to do some slight changes). So figured I’ll use Cubase. I can just open the Nuendo files and start where I ended.

But in the sessions, there is a little high noise, kind of a hiss on every channel, but it’s not constant. In goes in volume with the audio.
I first thought it was in one of the input channels, but after muting everything to the last channel: stil there.

All the settings look correct. So I thought let’s try Nuendo again and everything is clean…

Does this problem sound familiar to anyone?
I guess maybe something with the playback engine?