Contact Sensor showing Tampered, setting off alarm

My front door sensor has triggered the alarm at 2am and 4am over the last few nights. Says sensor tamper, although no one has been anywhere near it. Only seems to happen in the middle of the night, never during the day when the door is being opened and closed. Sensor cover is on correctly. Any ideas, anyone? Or do I just have a faulty sensor?

Hi @user62302. It would help if you could share a few pictures of the sensors placement. A Tampered error will only appear if the sensors cover is not on properly. There are some troubleshooting steps here that can assist you.