Apple Watch calories

Hi there,

I had a Apple Watch series 4 and have just purchased a series 6. I'm having trouble with the calorie counting. at the end of the day I seem to have burnt around 500-700 calories less in a day then I normally do.

im unsure if this is because the tech is more upgraded in the 6 so im getting a more accurate reading or whether is faulty in some way.

my workouts seem to have similar numbers once finished but my everyday, walking around work for 8 hours burns a lot less calories.

just wondering if anyone else has had this issue or if they can clarify whether I should consider getting my series 6 looked at or the tech is just better and the old reading was off.

thanks in advance :)