Octopus Energy (highly rated by Which?) have shot themselves in the foot on this!
I had a smart meter for many years which worked perfectly sending readings direct.
Last August they decided to 'upgrade' the meter. A replacement was fitted but technician couldn't get it to work. After much correspondence another technician came, with the same result.
The reason? This marvellous example of modern technology is programmed to work only off the O2 signal, whereas the previous one can pick up any of the main phone signals. Progress?
If Octopus had told me their new meter only worked off the O2 signal I could have saved them and me months of aggravation as the O2 signal here is non existant.
In fairness they have sent me £300 in compensation but I now have to take readings manually.