I did a 70 km ride yesterday that took about 3 hours 40 minutes, tracked on my Edge 130 Plus. The estimated calories burned for the ride was 158 (34 resting, 124 active). This seems outrageously low to me, particularly the resting calories. That works out to less than 10 calories per hour!
In contrast, I tracked a Zwift ride on my Instinct 2S watch (as an indoor cycling activity) and it estimated 115 calories for a 1h45 activity, which works out to about 65 cal/hour. This seems reasonable to me, and it's consistent across a few other activity types I've tracked recently with my watch (swimming, running, yoga).
I checked my birth date, weight, height, and gender in the settings for both devices, they're identical. I used the same HRM for both rides. I don't use a power meter for outdoor rides, but I have power readings from a Wahoo trainer for indoor rides. I don't think power or heart rate should affect resting calories anyway, though.
I also looked back at some rides since I got the Edge a couple months ago, and up until around May 20th the resting calories were also about 65 cal/hour, but it looks like sometime after that it dropped to about 33-35 resting cal no matter how long the ride is. Most of my rides have been 2 hours+ but i would think there should be a difference between 2 hours and 3 hours 40!