Daily calories barely any different between days of exercise and non exercise

[TaylahJG]

I understand that Fitbit tracks all calories (I.e throughout sleeping etc). I’ve had one day where I didn’t do any extensive exercise with little movement throughout the day and the next day had 65 minutes of active exercise burning a total of 400 calories (according to my Fitbit) and was also much more active throughout the day so would’ve burned more passive calories generally. At the end of each day the calories burned are extremely similar (only about 100 calories difference in total). I’m a bit confused as to why this would be? 

[JohnnyRow]

That does sound strange, but if you want to try to analyze it further, you could click on 'calories' on phone app, then click on the day, and see calories burned in 15 minute increments and see if you can make any sense from that.