I have just answered your support ticket on the subject - for convenience I am pasting my answer here as well:
Thank you for the provided sample code - we managed to reproduce the problematic behavior and it turned out to be related with the touch-scroll extender used in the Splitter. Commenting/uncommenting the three <br/> elements respectively disables/enables the scrolling of radPane22 and ListMetricsSlidingZone, which seems to prevent the click event of all buttons in this area. I am will log this issue for a further investigation, as for the time being you can work around the situation by disabling the scrolling of all RadPanes, having a child Splitter (so only the Splitter's scrolling will be functioning). For example:
I hope this information will be helpful for you. You Telerik Points were also updated accordingly.
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