I have an Optima G3 intruder alarm. Over recent weeks this has been falsely triggering between 3 + 5 am at random. So far I have replaced the battery, checked the PIRs for insects etc. All wiring is in securely and I can’t see anything that could be triggering a false alarm. When the alarm triggered the attack indicator is lit but no zone lights up. I can’t link this to recent work either such as decorating. Could anyone offer me troubleshooting advice please?