My brand new rain senior /Rachio app doing the same thing. Activating/deactivating 100s of times in the same day.
I experienced similar and contacted Rachio. I was instructed to wire it as shown in the diagrams online. It still continued to active and deactivate. I switched it off. Doing so allowed me to discover that I don’t need it. The weather intelligence is far superior and can be bypassed remotely if the user chooses to do so. I will disconnect and trash my rainbird sensor from my old system since it’s obsolete given the weather intelligence tech on the Rachio trumps it.
I just noticed that the original post is 2 years old so withdrew my reply.