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.
