Apple Watch Series 8 unreliably stand and move tracking

I recently bought an Apple Watch Series 8, which regularly tells me before afternoon that the stand goal (10 hours) has been achieved.

In reality, I've woken up, and since then been sitting by my table, working with my laptop. Sometimes it says stand goal exceeded even when I wake up, and I'm sure I haven't been standing while I was sleeping.

Calibration done by walking as instructions say, this behaviour has been present since unboxing it. What to do? Also the move calories seem high, regular office work day without any excercise and I keep getting 500 to 700kcal move calories which seems high to me.