I’m still struggling with this, too. Here is a work around:
On Gen 3 you can manually set the expected flow:
Zone; Edit; Flow Settings; Scroll to the very bottom under Calibrate;
Manually set Baseline.
Follow their recommendation of 0.5gmp. Once the system runs the zone, you might get an alert of high flow detected. If so, manually reset a little above the detected flow.
This will get you high flow detection alerts (like when a squirrel chews thru the drip line), but it will not get you low flow detection (like when the emitters get clogged over time).
My flows are 1.5 up to 5gpm which should be well above the .5gpm the flow meter is supposed to detect. Because I get high flow detected alerts when I initially set it at .5, the flow meter seems to be detecting, but the Calibration function is the apparent source of the problem…