System to slow at identifying movement

System not quick enough, motion detection runs 3 to 5 minutes may be more on some occasions,to notify me.

The system worked well at first,but know absolutely rubbish now, door bell is intermittent pick’s up movement only part of the time,had intrude on my property only caught the back of him as he left, also at Halloween people knocking on door didn’t pickup a single thing,loving at another system know.