How does Fitbit and MFP integration works?

[soxknitter]

I am confused about syncing between the two. 

I don't want to double my activity, but want credit for the extra calorie burn.

For instance, yesterday I spent approx 1.5 hrs at the gym: ran 5K, lifted wgts, and used the rowing machine.  Fitbit calculated the active time correctly, and stated I burned 513 cals based on my HR.

I then went home, put on my hiking shoes, and went for a long walk with the dog in the snow.  At the end of the day, I had logged 16,500 steps, and 2433 cals burned.  HOWEVER, myfitnesspal only gave me credit for the steps I had walked that day, not the extra active time. 

Is there a setting I don't have set up correctly?

Thanks in advance.

Moderator edit: Updated subject for clarity.

[SteveH]

Are you sure you're not getting credit for both?

I have my One linked to MFP and, like yours, it sends a calorie adjustment through to MFP when I exercise. However, this adjustment varies over the day so if I exercise for a second time I still only have the one adjustment in MFP, it's just bigger. Are you saying that your adjustment didn't grow after your walk?

[SunsetRunner]

I ran 1.5 mi , got credit for the steps but it only showed 126 calorie burn. Fitbit surge. iPhone 6+.