I have no affiliation with Hik. From what I can tell they don't even really seem to listen to their distributors.
I'm told that that they removed auto-tracking from the non-Acusense version of this camera as the gears are very small and they were wearing out prematurely. With auto-tracking...
I have the UK release and updated to V5.8.0 build 230519, Auto-Tracking and all other functions appear to work now - I'd be very careful uploading western firmware on a grey china import - last i heard you end up with china language only.
You'll find smart tracking tied to the VCA section.
I did, updated to 5.8.0 still the same and verified with supplier who checked their stock units running 5.7.4 that it doesn't work. They suggested downgrading to 5.7.1 using Batch Config but it came at the risk of bricking the PTZ - its installed in a soffit using a flush mount so PITA to remove...
Just got to be careful of IR or light reflecting back into the lens from under the soffit, your probably already aware of that though if replacing an existing PTZ. The cameras in question look great - DVS has a youtube video on these. Choose the 2MP 20X if covering long distance, 4MP 12X will be...
Their not 'indoor domes' they are a 5mp model which is not good for dark/low light environments - I have the 3MP version in the same format and its excellent at night (I don't even use the IR).
'Third stream setting is normally under 'Maintence' -> 'System Service'
From your description sounds like your just getting a notification and that LPR is active, have you tested it yet?
You should have 40meg of incomming bandwidth to play with between your 4 cameras, but keep in mind that this also include the substream (Mainstream + Substream x4 cameras).
I would look at dropping the frame rate to 15fps for any camera that is just for pedestrian traffic - I only use higher...
Check the record settings for event. Also bump up your bit rates, 6144 is a bit on the low side for 5MP @ 20fps with matching iframes. Change the settings from the NVR it will give you recommended bit rate ranges for your settings.
Consider switching to H265.
Get a proper outdoor PIR or microwave/dual tech motion detector - anything using the cameras own optics as the alarm/event activation will be flawed and cause too many false positives.