After the last update I have altimeter issue (garmin displays incorrect elevation, roughly 2 or 3 times lower). It has influence on the displayed gradient.
In addition? I found the some of the settings changed, for instance, Lap manually => Lap by coordinate.
Q to garmin development team: Can you make a hot fix and remove previous changes?
I have the same issue on 540 24.19. For example yesterday did a mtb ride and gained about 3500 ft of elevation according to GPS on my phone but Garmin only showed ~900ft elevation gain whereas before they would sync nicely between phone GPS and Garmin. Please fix!
It's amazing how buggy this thing is! What is it that you devs do all day? Are you guys high? Is the job part time? Im really confused as to why this is so difficult for you guys do get right!!? I'm a cardiothoracic surgeon and if I *** up this many times on my patients I wouldn't have a job 
