Fitbit to Garmin Migration, Calories are confusing

I recently migrated from Fitbit Charge 5 to GArmin Forerunner 265.

With my FitBit, I was getting these imports as a result of connected devices:

  1. Automatic "Fitbit Activity" kcal deficit imports (~700-900kcals)
    2 .Automatic "Walk/Run" activity kcal deficit imports (~200-400kcals)

Now with a Garmin Forerunner 265, I am getting only:
1. Daily Activity (Garmin) kcals (Activity Minutes, ~90kcals) very low counts
2. Recorded Garmin Activities like Running (~275-400kcal) seems as expected.

This is resulting in a significantly lower amount of imported calorie burns because I do not see anything (resting calories, etc) that is being carried over from Garmin as equivalent to the count from "Fitbit Activity."

I am not sure which one is accurate. I suspect maybe Fitbit was overriding Cronometer's algorithmic BMR calories, but I am not sure. Calories burned on a NON-active day seem to now be 2800-2900 with Garmin, with Fitbit these are often over 3000, even without any moderate or intense athletics, due to walks.

The Fitbit would automatically import walks into Cronometer and thus decrement walking calories (-140kcal, etc), but the Garmin device does not seem to automatically detect and import any activities, unless I explicitly start and stop them on the watch.

Going for walks is definitely a higher HR and higher kcal burn rate than a sedentary BMR calculation would be, so I am losing calorie counts. Is this an auto-detection problem in Garmin, or something I need to change in Cronometer?