Why are calories from an activity are not counted to daily summery?

I allways was thinking, why did I burn more calories over a day, when not tracking an activity, then when I go for example mountaineering the whole day.

today I did a test.

Today (sitting in the office) I burned around 300 active calories (nothing).

after work, i tried it out, while renovating a room I burned 659 calories.

Why aren’t they added to active calories summery on the watch or in connect.

that does not make sense to me.

could anyone explain that to me? 

I don’t know how long that is, but on earlier days with the watch, i had much more calories on active days, then now. Now it‘s the other way round.