Garmin R10 Hitting Downhill

I'm running into an issue with number accuracy when hitting into my net in my backyard. My backyard is on a slight downslope which is causing the R10 to read very low spin values, low launch angles and very steep attack angles. (i.e. 7.4 degrees down with driver) This also leads to a lot of roll out on my shots in the driving range and low shots in HTH and E6. Is there a simple solution that can help me trick the R10 into reading downhill as if it were flat? My entire backyard is on approximately the same slope. Is it a calibration issue?