FX8 hum (possible ground loop?)

[Bash_Man]

Hey everyone,
So I noticed recently my FX8 started to cause what appears to be a ground loop from the output of the FX8 to the Input of the amp.

Couple of trouble shooting steps I did:

• Noise is there even if I bypass the FX8.
• Noise goes away if I plug directly into the amp even if the fractal is still in the amp's loop (inline or bypassed).
• Bypassing loop or removing loop cables, the noise remains.

I am using Hum buster cables, however I built those myself based on wiring diagram I have.
https://wiki.fractalaudio.com/wiki/index.php?title=Humbuster

Going to check all my cables again and make sure all the solder points are good.

If everything passes and still have the noise, anything else I can check ?

Any help would be appreciated.

Thanks