Seen similar over the Mersey a few years back, just dead still above the tree line for about 4 minutes then gone in a blink. No sound either which is always the bit that gets me - planes and helicopters dont just go quiet like that.
What colour was it roughly? And did you notice any effect on your surroundings, like animals going quiet or your phone acting up? Those details matter more than people realise when you're trying to narrow down what you're dealing with.
Don't let anyone tell you it was a drone either, people are far too quick to throw that one out. Drones have a very distinct buzz and they don't hover that cleanly in wind. Post if you remember anything else about it, even small stuff.