Resting Heart Rate reading on Apple Watch does not match iPhone's on Health App

Hi there,

I noticed that lately when I check my Resting Heart Rate on my Apple Watch Series 5(v10.6.1), it never matches, although it used to, my Health App on my iPhone (v18.0.1).

I even considered the fact that my watch might be taking a snapshot of a shorter timeframe and my phone is giving me the average for the day, but since my watch is always smaller and the difference somewhat high (sometimes 5-6 bpm), wondering why the disconnect.

Again, they would always match before and have this feeling that this only started happening after my upgrade to iOS 18.

Thanks.