Rain Sensor stuck in loop

Last year I installed a Hunter wired mini click rain sensor on a Rachio 3 8 zone controller. It worked perfectly. I don’t know what firmware version was installed on it last year.

This year is a different story. Last May, after a rain, the sensor would activate. After a period of time, about the amount of time the sensor would start to dry out, the controller would start a cycle of flipping the sensor from activated to deactivated then back to activated several times a minute. This cycle will continue until I deactivate the sensor.

I watched the Rachio video on how to clean the sensor and followed those instructions. No change in behavior.

I contacted support. They said the sensor must have gone bad. I installed a new sensor. No change in behavior.

The old and new sensors both worked fine when I manually tested them before they got wet from a rain. The controller would cycle with no problem.

Since it worked perfectly last year I am wondering if the Rachio software was updated and has a bug in it. My controller is currently running version iro3-firmware-hk-5-640.

Anyone else have this problem?