Hello!
Need help to understand what this noise is, where it comes from and how to stop it. The clip is 3 seconds long and gives you an idea.

https://vocaroo.com/embed/c0OrLCX1ukJ

I just bought a UFX+ and I use an iMac Retina. I have used a Fireface 800 for a long time, sometimes together with a Ferrofish A16 mkII, connected with ADAT. The Ferrofish has added a bad noise which I think was due to a bad power supply, so I just asked Ferrofish to send me a new one.
Today I had a session and this noise appeared several times during the short recording session - it is recorded to all the 4 channels in use. I use the USB connection, between the iMac and the UFX+. The accordion player thought maybe it came from the ADAT connection between the UFX+ and the Ferrofish (they are still connected, but the Ferrofish isn't powered on). I didn't have time to try that solution. And it's not really a solution since I need the Ferrofish to work with the UFX+.

However, after unplugging the ADAT I played some music from Spotify via the UFX+ to the studio speakers and the sound suddenly became glitchy, raspy,  thin and "hollowed out" and stayed like that for about a minute until I turned it off and then on (then it worked) So that means that unplugging the ADAT is not the final solution. Please help! Thanks!

Screenshot of my Logic and RME settings in following posts.