Samsung multisensor staying open

So door sensor been in fridge a week battery 74% but now just says door open. Taken out of fridge and battery removed and battery refitted to no effect. Now out of fridge sat about 1m from hub with magnet attached still showing open. Temps transmitted. Any ideas?

I get this problem if the battery goes to 1%. You have to remove the sensor and the re-add it. Take out the battery and hold the button for 5 seconds. Change your batteries sooner but I would think 74% would be enough. For some reason with the new code or the app it “forgets” how to communicate with the sensor.