Hi ​@Ecomeco , it’s not usual for self generation to be included in your usage. If this is happening, then the installation wiring is incorrect. 
Any more info on why you think it’s being included?

​@BPLightlog, when I look at the readings on my Kaifa SMET2 smart meter, in the TOU Register, I can see that all the electricity consumption is shown against TO1 (and this is exact match for +A reading) - the remainder registers i.e. TO2, TO3, and TO4 are all showing 0.00 kWh - how can I resolve this?

If you only have a single rate tariff, it will all show as one ‘T’ reading. The way the system works, is for any solar generation to be used by your property (but not counted on your meter) and any additional need to be drawn from the grid. 
You should have a separate generation meter. 
Solar should not be shown on your Kaifa as a ‘T’ reading at all except for export

​@BPLightlog, What is a separate generation meter? - is that an additional smart meter that services my solar PV self-generated electricity 

...and I have two tariffs, a night one that is relatively ‘cheaper’ (and for charging my EV) and one that is ‘more expensive’ during the day - should this make a difference to the readings on the TOU Register?

a generation meter is not a smart meter. It’s simply a smaller device used to measure your solar generation. It is sometimes placed near the inverter if not in the main electricity cabinet

It will depend on your Kaifa model but with a dual tariff , I would expect to see a peak register and an off peak register. 
Are you being charged for peak and off peak (your bill should show this)?

@BPLightlog, Yes,  I’m being charged for peak and off-peak consumption - and yet, there’s only one reading on the Kaifa smet2 smart meter TOU Register, and that reading appears against TO1 only

The Kaifa register system is not straightforward unfortunately. 
As I said, depending on the model, there are various menus to see different readings - but none of these will show your solar generation. 

@BPLightlog, are there services on offer by experienced electricians familiar with solar PV and smart meters that one can use to diagnose and sort this problem?  - electricity suppliers don’t have an incentive to resolve this and solar panel installers tend to be defensive - would be great if one can be signposted to online services of experienced electricians - thanks

It is difficult to suggest any experienced electricians as they often don’t understand solar and installers are not always on top of standard wiring. You could search for a local installer and look at their reviews. 
Your supplier has no interest in this at all as it’s after the smart meter so not their problem. 
Just in case it’s of use, I did find these for a single phase Kaifa (if it’s the same model as yours).

This suggests the T02 should be showing your off peak usage. Hope you get it all sorted 

@BPLightlog, thanks - my T02 shows 0.00 kWh as does T03 and T04 - the only value is shown against TO1 - my experience has left a sad taste in the mouth - I now think smart meters are a disaster and the public should be told about the pitfalls of both smart meters, and being charged by electricity suppliers for self-generated electricity when then install solar PV - if I knew then what I know now, I won’t bother with solar PV install - but thanks for your input

If you are being charged separately for both rates, that suggests that the smart meter is working correctly. 
Also as I mentioned earlier, unless the solar install was done wrongly, the smart meter cannot register it as used or to be charged. 
Did you find your generation meter ? If not you need to ask where it has been put

Thanks ​@BPLightlog, I’ll ask my solar PV installer where the generation meter lives assuming there is one - looking at the total consumption for which I’m charged by my electricity supplier, I’m convinced they are including self-generated electricity and power drawn from the Grid in the total consumption figure - the Kaifa smet2 meter is anything but smart - despite the install, I still have to provide manual readings to my electricity supplier!! - I’d happily go back to my old meter if I could and rip out the solar PV and battery install