Brand New Omnia 2 constant random reboots

Hello, everyone.
I’m new here and hoping for some help.
I have a new Omnia 2 which constantly reboots. Sometimes uptime is a few minutes, sometimes several hours. It’s difficult to judge, but it seems reboots are more often with a high network load.

I have submitted a request to support 3 weeks ago, however nothing except a formal response was received, so I’m hoping for some help here.

So here is my story. I’ve bought a new Omnia 2, installed ssd samsung evo 500Gb as per video instruction, flashed latest medkit dated Jan 16 2020.
I did only a minimal setup via foris: WAN PPPoE and WiFi.
I also mounted ssd in order to save logs after reboots

> # crontab -l
> # DO NOT EDIT THIS FILE - edit the master and reinstall.
> # (/tmp/crontab.XXXXdGepOe installed on Sun Feb  9 00:06:17 2020)
> # (Cron version V5.0 -- $Id: crontab.c,v 1.12 2004/01/23 18:56:42 vixie Exp $)
> @reboot /bin/echo "####### REBOOTED" >> /mnt/sda1/messages_by_cron 2>&1
> @reboot /bin/tail -f /var/log/messages >> /mnt/sda1/messages_by_cron 2>&1
> # uname -a
> Linux turris 4.14.158 #0 SMP Fri Dec 20 00:24:37 2019 armv7l GNU/Linux

I have almost no experience in troubleshooting hardware problems.
I haven’t found anything interesting in /var/log/messages so far.
Is there any way to increase debug level? Any other logs to check?
Any suggestions on how to troubleshoot my problem?