I would suggest reading this thread:
https://community.rachio.com/t/flow-meter-not-working-rachio-please-help/17163
It is possible you are going above the 25gpm limit on the one zone. The other possibility is that your installation is marginal. The asymmetric flow created by a marginal install would get worse with higher flow rates. So, it could work well on low flow zones and then have a problem with a high flow zone.