Keep getting High Flow detected message in 1 zone

I keep getting a high flow detected message in 1 of my zones. When I calibrated it (3min), it read out 12gpm. But when I run the zone for 10min or so, it give me somewhere between 14-15gpm. I couldn’t find any leaks anywhere and the irrigation system just got installed. Is there a potential leak underground? Or should I just run the calibration for 10min instead to get a more accurate reading? Maybe 3min isn’t long enough to full pressurize the system or something?

Any help would be appreciated. Thanks.

More information. So I set the pressurized timer for longer this time (7min), and got some really inconsistent results. I watched the monitor as it calibrated it and it would jump from 15 down to 6 and back up to 11 and so on until it landed on 11.8gpm. Is this expected?

Also, I haven’t seen this with my other 2 grass zones. It’s only the front yard zone. Maybe because it’s closest to the valves and where the main water comes in?