Aeotec Zwave Controller and Openhab3

After more than 15 days, the z-wave stick switched to offline.
I did not do anything special, appart perhaps installed a reboot-shutdown-switch following rpwong clear explanations.

I think that it stopped working when I rebooted the raspberry.

Option 1 and 2 are ticked on the raspberry config “prepare serial port” page; serial port of the stick is set to /dev/ACM0

Any idea of what could have happened ? And suggestion to solve my problem ?

Honestly, I am fed up with this Zwave stick problems …

Thanks for your assistance.

Sam.