Look Keo cleat lifting problem

I had a very similar problem with Look Keo Classics which, as a triathlete, caused me no end of grief and effectively put me out of competition for a year with achilles niggles. The Keo Classic platform, with slightly worn cleats, basically lets your foot roll (in the aeroplane sense - i.e. around an axis parallel to the direction of travel, as opposed to pitching around the pedal axle or yawing to unclip).

It was only when I realised I had a particularly sore ankle after riding one specific bike that I twigged that the problem might be pedal-related. My other bikes all had the Look Keo 2 which has a much wider platform and basically stops the side to side rolling, which your calf and ankle will otherwise battle against causing pain. Swapped the pedals for Keo 2 on my main training bike and have never looked back.

Worth noting that even on Keo 2s, worn cleats will eventually let your ankle roll. I would hazard a guess that this has become more of an issue since Look introduced the rubbery "grip" think on their cleats, they seem to last barely a couple of months before they're loose again

Do you always unclip only one foot? I always unclip the right, as such my right Keo cleat wears MUCH faster, compare the thickness of the cleats. HTH

I've had a similar problem was doing my nut it was a clicking or clunking mid stroke in my case. It might be worth taking the pedals out and re tightening them in the cranks, worked for me.