This video goes over phase(leg) detection issues:
“Significantly more” in the sum of the Bubbles could be from the fact that the 2 phases you have are at 120deg … so you have 208V nominal. Do you know if your power feed is from a three-phase?
When Sense “splits” the legs it will put the 120V watt calculation in what it thinks is the appropriate Bubble (bucket). I believe then it could do a mis-calculation because it’s multiplying the measured current (per leg) by 120V vs what should be an effective 120*0.866. Then again, this could be completely wrong!
More about a three-phase install here: