I had a similar problem with several Everydrop flowmeters. I started with two unwired meters and, after about a year of use, I began getting reports of 0 flow and blank displays on the meters despite the fact that the irrigation system itself was working properly. I replaced the unwired flowmeters with wired Everydrop flowmeters and things were fine for a while. Eventually, however, one of the wired flowmeters began behaving the same way as the earlier unwired flowmeters. I took it apart and found that the flowmeter had developed a leak between the flow stream sensor and the electronics compartment - probably due to the fact that the irrigation system was tapped into the street pressure side of the house pressure reducer. The irrigation system is now on the house side of the pressure reducer and the remaining wired Everydrop meter seems to be OK.
Still, I replaced the failed wired Everydrop flowmeter with a Flomec flowmeter. More expensive, but worth the peace of mind.