I suppose it could be a firmware issue...?
Example using tripwire and intrusion together, I get great results
No h.265
No smart codec
Period is set to 24/7
You already changed the min/max size..
How are you verifying rule activation? Do you have smartpss? You can view it live and see if the rule line is flashing red when tripped. Look in playback and see colored hash marks for IVS events?
I wouldnt rely on DMSS app notifications myself..