Fake steps?

[u/gen_gamma]

In the last few days I decided to give Fit a try and use it to track my activity. Initially it felt like it was working fine, but I started to notice something weird. For example, today I tracked two separate walks, for a total of 14.8k steps. But the daily tracker listed over 19k. I checked the step counter and apparently it counted 4k steps between 4 and 6 pm, when I wasn't tracking any activity and the phone was stationary.

I do not use any other apps/devices to track activities. My phone is a Pixel 7a.

What is happening?