@Wayne-TP Thank you so much. It was the Tapo Application, automation section had created a link to all the devices. I've removed it and now they are working independently. Not sure why Tapo app did...

I have 5 x HS100 devices for years. All work perfectly as I'm considering buying the Tapo plugs, I decided to download the Tapo application. Installed perfectly, and added all the Hs100 plugs...