Thank you - quite a lot to go on there! Regarding there being a lot of individual areas - I do have three other identical cameras that have far less trigger events, but they also detect the cat!!!
A few points/observations on your comments.
1. Is it necessary to set minimum/maximum sizes when...
My cameras are DS-2CD2346G1-I/SL running V5.6.0 build 190507
My NVR is a DYN 7608NI running V4.21.005 build 190509.
I've attached a screenshot. In case you are trying to ascertain if I have ticked "human" - yes I have
cheers
My Accusense camera alarms are constantly being activated in the middle of the night by next door's cat. He is quite a bit boy but nowhere near the size of a human which is what they have been set to detect. I read about complicated algorithms etc but mine don't seem to work.