Apple Health miscalculating distance and draining battery in iOS 26 on iPhone 15 Pro Max

I walk the same walk every morning. I updated Tuesday 09/15 afternoon on my iPhone 15 Pro Max.

Since then, Apple Health is shorting my distance by at least 25% (yes, all emissions are allowed to the Apple Health app.

I used to come home from a 9 mile walk with at least 40–45% charge and now it is at or near zero.

I do NOT like iOS 26 one little bit. :(

[Re-Titled by Moderator]

Original Title: Apple Health in iOS 26 is miscalculating distance by about 25% and the battery life is AWFUL!