Low Battery indication on Wireless Flow Meter after replacement

I received a low battery notification for flow meter after about 10 months and replaced the battery. I ran the recalibration of all zones but the battery still shows low battery condition. Ok, maybe I had a bad set of batteries so I replaced them with another new set. I even allowed the system to show no flow meter available before replacing with the second set of batteries. The meter refreshed with excellent signal but still indicating low battery condition. Any thoughts on what may be issue?

I am having the exact same issue.
Rachio Wireless flow meter installed Sep 2018.
First Battery low indication on 11-Jul-2019 (~10 months)
Replaced batteries with fresh (Dec 2025) pair.
Low battery again on 26-Jul-2019 - replaced again but soon after started seeing lots of lost/reconnect messages.
Replaced batteries again tonight (different brand) (removed batteries were down to 1 volt)
Distance to meter is about 20 feet through only 1 stucco wall - signal strength says 6 (Excellent).

Plotted to see if there was a pattern (such as an obstruction or interference):

Worried that my warranty is about to expire.

Searching on Rachio help for flow meter lost connections but the Rachio site linked to an article on Controller connection issues (different radio!) Article suggested updating firmware (current: iro3-firmware-hk-5-61) 5and App offered Update Now… but it never completes after saying Updating…

I have the same setup as you (below ground) about 20-30 ft away from controller. Signal strength not an issue. I started getting more connect/disconnect notifications over the last few weeks. Replaced with latest greatest copper top batteries and still received low battery status indication. I hit my limit on troubleshooting and contacted Rachio tech support via their email system. After a few back and forth messages they agreed there was something wrong with the flow meter. They are sending me a new meter with no questions about warranty. Glad to get this resolved but not looking forward to reinstalling the new meter. Best of luck.