I’ve been using my Rachio 3 for nearly 2 years now with flex daily. After the initial setup, it ran fine, then last summer I saw some brown spots so was trying to tweak the advanced settings. Ever since then, one of my 3 backyard grass zones, “Backyard Mid” always runs for 4 minutes, while the other two zones do 12 minutes, soak, 12 minutes. So there is a huge difference here, but I don’t see any difference in the zone settings. I’ve tried resetting the advanced screen settings, but that zone still only runs for 4 minutes.
Double checking just now, there are slight differences - root depth of 5.9 vs 6 inches, and the efficiency setting was slightly lower. But these don’t explain a 6-fold difference in watering times.