There is a menu option to calibrate the touch screen, that may or may not help. And is the unit's firmware up to date? You can check Clarion's website in the support section which can help you determine if the software is current and how to upgrade it if not.
I can tell you my NX501 also started having issues, sometimes it would "lose" the Sirius, sometimes it would fail to load the Navigation, sometimes the unit would just "freeze" and not do anything until I pushed the tiny reset button. Started happening more and more often. So several months ago I decided to upgrade and replaced it with a Clarion NX706 which has performed flawlessly. I chose another Clarion for its features, and it also made the swap much easier since the main wiring connector was exactly the same.
The new Clarion has additional features which I utilize including a HDMI input (hooked to my dashcam) and rearview camera audio input. So far I am very happy with the unit.
2014 Seneca 37TS
Toads: 2014 Ford Explorer Sport or 2013 Ford Focus ST