Screen Time show 24h usage

I recently installed Big Sur on my MacBook Air (Early 2015). I made a fresh install, not un upgrade.

When I opened Screen Time I could see that a 24h usage is logged for every day.

"aka.ms" Safari. I use more Apple devices, but I filtered just for my MacBook Air, and it's from this device only.

I figured out, that this webpage is connected to Microsoft, and the only related app is Microsoft Teams, which is installed on my computer. Screen Time show the correct Teams usage separately.

Can you help me, what can it be?

Thanks!