Issue - re-pairing UK Power Sockets to Hub

I’ve just purchased and installed a Smartthings Hub with 2 x UK Power Sockets. Everything was fine until the sockets stopped working via the app, so I removed them in the Smartthings app to try and re-install ( I believe I did the full remove).

I’m trying to re-add the sockets again via ‘Add a Thing’ but the app can’t seem to find them. I’ve logged into IDE and my hub is listed but no devices (other than my iPhone).

Note these are the UK Socket Plugs without the pairing button on the front - they have the on/off button on the side.

I’m sure this has been answered before on here, but I can’t quite see the guidance! Appreciate any help, thanks!

When searching for ‘things’ click the side button a couple of times… usually works for me