Interesting. Sounds like you are comparing daily Sense vs. daily Utility ? My take is that you should do a little more investigation before reseting.
You might have already read this, but it gives a good idea of expected accuracy as well as the reasons why people weren’t initially seeing a high-degree of accuracy WRT to their meter (everything from a hidden additional sub-panel, to estimated reads by the utility, to reversed billing with the townhouse next door).
One useful thing to try would be to compare hourly usage if your utility provides that data (min provides 15 min data). A time-of-day based discrepancy might give some clues.