Ur22 grounding

Hi does the ur22 ground itself or is it grounded via the PC’s power adaptor.

Reason I ask is because I’ve spent 2 days eliminating all possible curses to buzzing electrical spikes when touching any metal part of my guitar that’s running through the ur22. I also have the issue with ur22 gain peaking when input gain is only on 3.

Now this problem only happens when the ur22 is receiving it’s power via a powered source that has a 2 prong power adaptor. I’ve tried it on 2 other PC’s that have a 3 prong power adaptor and it eliminates all issues.

Is this a grounding manufacturing over site? Or does the ur22 gets it’s grounding via the PC.

I’m in Australia and I’ve spent 3 days eliminating all possiblities and I’ve came down to this.

I know a few people have the gain peak issue I wonder if they are getting it because of the power adaptor isn’t grounded.

Like I said it all works fine when ur22 is connected to a PC that has a 3 prong power adaptor. The 3rd prong is for ground.