[s905x2] X2 Cube - spontaneously reboots itself

Have two boxes X2 Cube (s905x2)

They spontaneously reboots (but i don’t know CE or KODI) itself. It may be after 1 hour or one time in a day or many times in a day. It happens when box just power on but nothing to do.
There was never a reboot while watching movies.
This problem was on night build and on stable.
I changed SD, power supply, fresh install and nothing :frowning:

Last 10 hours was 3 or 4 reboots
logs after last reboot: http://ix.io/1VQT http://ix.io/1VQW

PS: uptime dropping after self reboots