Aqara door sensor false readings / sticky readings

I’ve been using an Aqara door sensor for over a year with wires to a rain PCB to detect rain and trigger automations. I removed the original reed switch. Today the sensor stopped working and I noted in Zigbee2MQTT it stated 0% battery. I swapped out the battery but now I’m getting sticky readings from the sensor, in that if I open or close the sensor quickly, it can stick open when it’s really closed or stick closed when really open. I’ve tried re pairing to a different Zigbee node (powered Zigbee device) but it’s the same. Can’t work out why it’s doing this…