Apple Watch doesn't track calories

I recently started using my Apple Watch 5 actively again, and I've noticed that when I'm using the training-app when I go for walks or a run, it doesn't track the calories. The total amount of calories is still zero when I'm done. It has happened during my strengt training too, but sometimes it works. I have tried to update both my watch and my phone, but still it won't work and it's getting a bit frustrating. The amount of steps, speed and kilometers I have walked is correct, it's just the calories that's the problem.

What can I do to fix this?? It's a pretty expensive watch, so to buy a new one is a bit extreme.. I feel like I have tried everything, and there is nothing wrong with the settings or my personal details.