Thanks for the link, although their information is pretty useless. I dont know any sane person with any sort of remote common sense who would not check that all the small bits are there. It's the first thing I checked.

As for the design, it seems pretty awful. Shimano's setup is so much more simple with the preload then pinch screws. None of this spring washer for preload and a bit bolt that comes loose all the time. Very disappointed in this tbh.

I'll get a new spring washer and hope the tension will be able to take up this 'slack' and loctite the threads to stop it coming loose.