It’s described as a “stealth” ship but it was still picked up easily enough the British’s radar?
Stealth on a ship is a hoax.
Stealth in a ship is similar to stealth on a plane, in that it is about making the target harder to detect. not impossible, just harder. However, as ships are much bigger than planes the point for stealthy ships is not to make them disappear in the clutter and noise, but rather to make a large naval ship appear to be a smaller non-military vessel. In a busy shipping lane that can allow a vessel to get closer than it would otherwise be able to do, at least close enough to launch its missiles.