Low flow messages

I got low flow messages on the last 3 zones last night. Calibration runs had 6.3, 10.5 and 10.5 gpm. Low flow was 5.1, 7.5 and 8.1 gpm. I assume it was low pressure. We use a reclaimed pond water system that is shared by a large neighborhood. I don’t get the messages often but I have the low threshold set to 85%.

The total flow was 66 gallons lower than in the past for 1 of the zones. The run time therefore didn’t change due to the drop in flow.

If I keep getting these low flow messages what should I do? If I change the calibration gpm manually to a lower gpm would that mean I’d overwater sometimes?