Impossible to update Command Line Tools (OS X 10.11) for Xcode 7.3 on El Captain

Hi,

I did update El Captain by downloading the Combo Update, but now the App Store keeps showing that I need to update Command Line Tools (OS X 10.11) for Xcode 7.3 on El Captain. However, when I click update, it downloads everything, starts installing, and then shows again the update availability. As well, if I look at the list of the latest updates performed, it has already been installed. How to solve this?

Thanks,

Massimo