Significant discrepancies with Husbpot Email metrics?

I have a Hubspot account connection that is reporting significantly different numbers in Power BI (through SM connector) from what I’m seeing in the Hubspot UI. Sends and delivers are the same for these emails, but unique opens and clicks are not. 

According to HS, they process bot traffic before the API, so it shouldn’t be reflecting bot opens (I’m assuming this includes iOS mail apps, but HS hasn’t outright confirmed that). The other idea I have is that the metrics are being aggregated daily and unique clicks by day might include a returning user - but altering the query to just return a single row per campaign (rather than events for each date) shows the same wrong numbers. When performing this same adjustment in the Hubspot API explorer, it works fine. 

For reference, one of these emails shows 1,138 unique opens and 311 unique clicks in Hubspot itself. By contrast, Supermetrics is reading 2,591 opens and 388 clicks (when date is an added dimension) or 2,075 opens and 318 clicks (when date is NOT added as a dimension). 

Has anyone ran into similar issues and found a fix? I’d love to get this to 1:1, but I’d settle for event +/- 10% if I can explain the difference in the numbers. 

Thanks!