Has anyone had any experience using a SD Mixpre-6 with a Panasonic GH5? I am getting a healthly amount of noise when I return the sound back into the camera. I don't hear any noise when I monitor the sound from the Mixpre-6, just when I monitor from the camera. I've used these guidelines that SD has provided. When I used the Mixpre-6 with a Sony A7sII, I didn't get any noise/feedback at all - just clean (albeit quite loud) sound. Any suggestions on how I might troubleshoot?