This is one of the meters that ties around the breaker right. I am using a clamp meter doing the same thing. This is odd. But these meters are generally pretty darn accurate. Does your breaker have 1 power lead or two (bigboi 30amp break).
Yep, it's 220v so 2 hots. It's only a 20 amp breaker, but I only have the one miner so I am well below max current draw. It's also a short run, miner is 10 feet from the panel. I use the exact same model watt meter for my EV charger and it reports fairly accurately there as best I can tell. I may pull the EV charger one and make a "home made watt meter with outlet" and plug miner into that and see what that reports. If they report the same then I'm not sure where to go from there. Just a very bizarre scenario!