Error: Overnight heart rate readings wrong 21 Feb 2026

With my less than 2 month old Forerunner 265, my over night heart rate was about 25 to 30 BPM lower than usual the entire night last night, starting at about midnight when I went to sleep.  I know this for a fact because I have another HR monitor I wear at night.  Whats worse, I am training for a race and the error with my Forerunner threw off my Acute load, which appears to be erroneously lower by about 25%.  (I know this because I am tracking ATL in a separate spreadsheet using the weighted average formula found in the forums.)  Body battery and other metrics are way off now!  Has anyone else seen this? Is this a known bug? Thanks!