My health activity tracker was paired with another iPhone

I’m using iPhone 11 model and I don’t have any Apple devices other than that, recently I checked my health activity tracker and I found that my device was paired with another iPhone and I deleted it right away, however I do have some doubts so again I checked my data’s and it shows hardware version 12,1 I could not figure it out can you please anyone help me with this issue thank you.

[Re-Titled by Moderator]