My Kleos sounded a little off lately, so I thought it should be checked out. I sent it to Andy Kim. It turns out all that was needed was the stylus required a cleaning and polishing.
Glad you got it looked at by an honest guy and kudos to Andy Kim (whom I hadn't heard of before this thread).
I can no longer count how many times I've had cartridges shipped to me for inspection, supposedly because (according to the owner) they were wearing out or defective, only to find that a simple but thorough stylus/cantilever cleaning brought them fully back to life. It's always the first thing I check, and usually the last that I have to. :-)
Stylus cleaning after every side is mandatory to maintain performance, especially with cartridges having advanced stylus profiles like the Kleos. Modern styli rely on very small contact radii for their clarity, HF extension and low level detail retrieval. The tiniest amount of smudge interfers with that.
This is true even if your LPs are very well cleaned. As JC taught me years ago, a perfectly clean groove will shed vinyl particles. The heat and pressure at the stylus/groove interface bond these to the stylus. Cleaning after every side is the surest way to avoid incremental buildup of smudge.
Routine use of a Magic Eraser (followed by a soft brush or a dunk in Xtreme Phono type goo) will maintain a stylus in as-new condition.