I've had similar experiences with UK recruiters, and heard the same from colleagues and friends in the industry. Recruiters there seem to gather a lot of applicants for a role, promise the world, then drop most of them.

I have had good recruiters in the UK but they're few and far between.

Best to treat them like company contacts. Let them apply for a role or two for you, and contact somebody else for another role. I used a dozen recruiters at any one time when I was last applying in the UK.