First Ride Impression - GREAT (but there is an issue with calorie burn)

took the rally 200's for a first real ride today. outstanding. calibrated once at the trailhead and again about 25 minutes later at a bridge crossing i had to hike over. clipping in and unclipping were flawless and just like normal spd pedals. in fact, there was no real way to tell from riding that they were power meters. no issues with rock strikes so far but i did clip a root at one point. all of the data is pretty amazing and seems accurate (compared to my indoor trainer).

one issue, however, is the calories burned for the ride is ridiculously low. it showed about 600 calories for a 2+hr ride. the exact same ride before the rallys were installed (and using just the edge 830 and a hrm) would show 1200-1500 calories for the same effort, so something is very wrong. i understand calculating calorie burn from power is far more accurate and i get the logic behind it, but it seems that the implementation of that logic is flawed here in that it is ONLY calculating calorie burn when watts are being produced, completely ignoring heart rate. if i'm spending 2 minutes at 160bpm hiking the bike up a really steep section, garmin's telling me that counts for 0 calories? 0 calories for going downhill, stopping for a drink or doing literally anything other than pedaling is just incorrect, but that seems like what's going on here. when i started noticing the issue i took a break at the side of the trail for a few minutes and the calories didn't move a single digit the entire time. how to fix this?