I have a Garmin 735xt, I configured my heart rate zones based on HRR.
All seem to work ok, the zones show correctly on my watch, and also the results in Garmin Connect when I look at the HR graph.
The problem is that the Heart Rate Zone percentage bar charts show the wrong information, i.e. show results much less the actual.
For example most of my run was in Zone 3 in my case its (143 - 156) the Avg HR Zone shows as 3.3, but the percentage bars below show as if I spent 35% in Z1, 35% in Z2 and 21% in Z3, which makes no sense.
I included below snapshots of the graphs