Tracking not accurate

I have a question for Apple watch users. My fitness tracking data has started to go way off track. For example, on Friday I did circa 2300 cals and 30,000 steps when I checked before going to bed, and then when I have come to update my spreadsheet it has reduced down to 1900 and 25,000 steps! It still has every workout logged though. I always hit my calorie goal of 1600, yet yesterday it was saying I only achieved 799 cals. This is impossible as I played tennis for an hour, practiced some golf chipping and did a 5ish mile walk.

This has seriously pee'd me off as now I don't trust any of my spreadsheet data and am worried that my tracking/analysis may be off.

I have a newer series (series 5) as I upgraded last year.