Tides (2018) signal bleed

I bought a Tides second hand a couple of weeks ago. I’ve noticed that when in frequency mode the signal bleeds thru the power connection. I can hear it in my headphones (connected to Doepfer A139-2) when I have disconnected all patch cables. I don’t have this issue with my other sound sources (all MI modules).
I have tried to move it to the second line of my µZeus FBB without luck. I’ll try to disconnect all other modules later when I have some more time to spare but in the meantime I’m looking for advice.

Ferrite choke?