HKC Alarm going off on night set

Hi all,

hoping somebody can answer a question or give some guidance. Have a HKC alarm - fitted 3 years ago and generally very good. However, last 3 nights when we’ve set the ‘night set’ on it - it’s gone off about 30 minutes later and in the log it says ‘delayed entry’ which doesn’t make a huge amount of sense to me. Reset it again and about an hour later the same thing.

Seems

to be absolute fine on full set.

Tonight I set it and again, same thing. Any ideas?

Thanks, John.