FYI I have the same issue using a Canon m50 and the dr60d mkII that when they are both connected to the same usb powerbank the camera out is nothing but hum on both the low and high outputs. It was resolved by using a KRIPT Noise Filter Ground Loop Isolator I purchased for somthing else. Luckily I had it lying around. I got it from Amazon for like $9. Unfortunately the usb port is very fragile and mine broke the day I got it.