Amazfit has released firmware version 5.0.2.1, an update available for the Amazfit GTR 4 and GTS 4. Not only does the new software address multiple bugs for the pair, but it also introduces a new heart rate algorithm designed to improve accuracy during workouts.https://www.notebookcheck.net/Amazfit-brings-new-heart-rate-algorithm-with-enhanced-accuracy-to-popular-smartwatches-via-latest-update.770588.0.html
What about the GTR 4 LE?
It has the same hardware as the GTR 4 but didn't get any update...
Another update today 5.0.3.1, smaller but with a lot of changes (I didn't bother to read, lol).
After the update my gtr4 watch battery drains completely after 2 days (instead of the 2 weeks that used to last).
I haven't changed any setting, I'm sure this is some issue with the Zepp app, since I moved to Notify the battery last a bit longer (roughly a week).
I'll end up getting rid of the watch if I have to recharge it too often.