Active calories are too high.

I have no idea how accurate the active calorie counter is. However, I would like to point out that the calorie counter is based on heart rate (in combination with age, weight and more). If you are saying that you just laid in bed all day, then I guess the number might sound too high -- but the step count alone is not really enough information to consider it inaccurate.

Thanks for your kind reply. 

I think there is some problem with the way active calories are calculated. Just to give you an example of my hypothesis, if I finish a running workout and right after that start another lesuirely walking workout and then take 1000 steps in the walking workout I'll burn about 40 calories. Right after I finish my walking workout and now take 1000 steps without any workout started I'll burn close to 150 calories. In both cases all my statistics such height, weight etc is the same and even heart rate is in the same range. Whereas the 2nd instance gives me so many extra calories. 

You could set a lower activities class in your profile. I know that on a normal day I take about 3000kcal to keep my weight, so I adjusted the activity class until it matched that approximately.

Also keep in mind that the total kcal statistics of an activity also includes your base rate.

Wouldn't setting a lower activity class give me more calories during activities. I have the opposite problem, I think my non-activity step calories are exorbitant 

I find how Garmin calculates the walking calories to be very, very poor and I wonder if they might actually display gross calories on top of TDEE, thus double dipping. When I do longer walks then the calorie burns are ridiculously high, despite having properly tested HR zones. My running and cycling numbers look not too bad though.

Note that it doesn't seem that acvitvity class should affect the calorie burn rate, except on "older devices":

https://support.garmin.com/en-US/?faq=DJEru6ns626MZTh2kvUXZA

But I guess you only used it to affect the expected daily calorie burn. I haven't tried to change it myself.