How to use j Rockett Archer guitar pedal with Archtop Acoustic

[ChapinFan]

I have a J Rockett Archer IKON Guitar OD / Boost pedal that I really like. I am trying to use it with the Mesa Rosette 300 Acoustic Amp. I would also like to record it using the Steinberg UR22 MKII USB Digital Interface.

My problem is I am getting a pretty loud Buzz with it. It doesn't seem to be too bad until I actually go to play. Meaning it is pretty silent until my fingers so much as fret a string and then the buzzing starts If it is played with distort mode on, of course, it isn't very noticeable. But if I am going for a clean boost, I still get a very noticeable buzzing.

I am using a Guild Savoy 150A guitar, which uses a passive DeArmond Rhythm Chief 1000 floating pickup.

I really like the Archer. When I go straight into our church PA system (An Allen&Heath mixer) I don't seem to be hearing a buzz. But I pick it up on the MESA Rosette and I pick it up when I am trying to lay down a track in a DAW using the Steinberg UR22 -- and it doesn't seem to matter what hardware I am using, nor what software. I used a Mac with Garage Band, a PC with Reaper, and Studio One, and an iPad with Cubase, I still get the buzzing.

I have tried the rockett plugged into an isolated power, that the MESA was also plugged into. I have also run the Rockett on DC power. Still getting the buzz.

Any suggestions of ways around this?