I develop racket sports apps and a log time ago I reported an issue that HR rate recorded by 3rs party CIQ apps is way lower than the one recorded by default apps (https://forums.garmin.com/outdoor-recreation/outdoor-recreation/f/fenix-7-series/369676/low-hr-rate-recorded-during-activity). It used to happen on Fenix7 then was fixed for a moment and is back again (approx 7 months ago).
It used to be a Fenix7 issue exclusively, at least accoring to my knowledge, but right now I'm floded with complains from the users that this issue it happening on various garmin models (Epix, Venu3, Mk3 and so on...). Is there any light of sight to fix this issue? This is a fundamental feature of any activity recording and based on what i know users are not only giving up on my apps but also on Garmin devices as well.