Looking at the map of the UK, there are hub gateway earth stations at Goonhilly and Chalfont Grove, plus the Isle of Man. To connect to the internet there must be one or more Starlink satellites visible from both your site and a hub gateway. The satellites are at 550km height. Min elevation angle 25 deg. Coverage circle 941km radius. I think the coverage animation assumes a higher minimum elevation and smaller radius circle, about 450km.
During the Beta phase there might be occasional breaks in the service due to gaps between the satellites. Also, there will be very brief breaks when switching between satellites that you are unlikely to notice.
See
https://satellitemap.space , click Tools(3 tiny gears), select Circle option and input your lat/long, and see the coverage as the satellites move over your location. The circle must include your location and a hub gateway side.
There has been speculation that pigeons standing on the dish edge might cause complete outage of 20 minutes. My opinion is that a pigeon on the edge would cause a degradation of the signal which might cause loss of service if combined with rain and low elevation angle. It helps if your dish has a wide view of the sky as the direction of pointing changes all the time. Once a satellite goes out of range your pointing must flip back to find another approaching satellite.
For those joining the Beta trial program the cost for Starlink is $499 for the antenna and WiFi router, plus $99 per month.