Active calories not counted or changed

Hi, For the past few weeks, when I do a workout with the Garmin Edge 1040, the amount of active calories (not counting resting calories) doesn't match the total active calories displayed in Garmin Connect for the day.

For example:

Active calories cycling: 1100

Resting Cycling Calories: 115

Total Cycling Calories: 1215

In the summary of the day in Garmin Connect, I would expect to see at least 1100 active calories, plus the calories from steps and general activity. Instead, in the example above, I see 880 calories burned in the daily summary. Or sometimes I initially see the correct amount of calories, but then it changes, decreasing during the day.

I have both an Edge 1040 and a Fenix 7, updated to the latest software version, but I only use the Edge during the cycling activity.

Do you know how this happens?