I really doubt there is any difference in the Ring software from the US and the UK, other than language specific included resources. The z-wave frequency is different in the US and the UK (so I’ve read, have not proven), so make sure the Ring base station was purchased in the UK.
Also, the Ring alarm costs almost twice as much in the UK compared with the US. Really supprised with the price gouging they can’t afford to spend resources on approving ‘works with Ring’ devices in the UK.