Apple Watch hearthbeat and breathing during sleep.

Hi all, i recently bought a Apple Watch series 11 and have issues with my sleeping app.

The first night my apple watch gave me a nice overview of my hearthbeat (BPM) and breathing frequency over the night together with my sleepfases etc.

Now the 2nd and 3rd night i can't find all this data anymore (hearthbeat and breathing frequency).

It fits really well around my wrist and is not loose at all, and also energy safe mode is not switched on.

Does anyone has the solution to solve this?

Thanks in advance,