Sudden restart Fenix ​​5 plus during activity

Hello, I hope to receive a solution to my problem. I recently purchased a fenix 5 plus and already from the first activity (cycling with preloaded gpx route) I encountered an anomalous restart of the device. This occurred in conjunction with the end of the last climb detected by the "climb pro" function, active on the clock. The same day, trying to enter the "climb pro" settings, I realize that the device restarts as soon as I enter and exit the "data field" section of climb pro (when I enter a black screen is generated, sometimes with a band white, and when I exit the device restarts). I initially tried to hard reset the device, following the guide found on the garmin site which says that you must also delete all the .FIT files contained in the various folders of the device. Then I tried to install the 16.71 beta firmware. In both cases the problem remained again. Also remains the problem of reboots when I enter the settings of climb pro. What could be the cause?