Stupidly I bought some Sonoff S26 plugin smart switches (cheap). They look identical to the rounded Kasa HS100, only difference is indicator/switch is below the actual socket pins on the S26.
All of the S26 switches do not work, for whatever reason. They will not pair to virgin media hub4. Hours and hours of trying.
In desperation I bought a single Kasa HS100, which linked and paired to hub within just a few minutes. DEEP JOY
So I am going to bite the bullet and dump all the Sonoff S26 switches, and buy HS100.
The problem I know have, is that I have a number of Sonoff TH16 (Temperature and Humdity measurement) and Powr2 (Wifi Switch) modules that were going to hardwired into a plastic cabinet.
I have not tried to see if they work, as I have lost interest with the problems encountered with S26 switches.
The Powr2 switches I can probably use a TP-Link 3 way Power Strp
However is does not appear there is anything compatible in the TP-Link range to measure temperature and humidity (with remote sensor)