I still have since months the problem of the random reboot.
I've tried getting OTA update but the service of firmware update check gives me error.

Any news?

It looks like an hardware fault . If updating to latest firmware + factory reset doesn't solve the issue, please contact your seller for a replacement under warranty. I can now confirm that my hardware is broken, so I have to rpalce it. Is there a quick way to buy a replacement? I'm skilled enough ...

Of course it worked only after updating last version of OS and performing full reset.

I have a different problem with the speaker, the same stated in this video:

https://www.youtube.com/watch?v=PHYpo6uPvBI

Solutions?

Same issue for me, but it seem I've solved disabling DuraSpeed.
Will stay tuned.