LG G Flex 2 H950 Random rebooting

Hi guys!

I bought one of those LG G Flex 2 H950 @ US9 on eBay from Qualitycellz. However, my unit seems to have some issues...
It does not matter what I am doing on my phone, does not matter whether I am using a SIM-card or not (I tried the phone with and without Sim-Card), my phone keeps rebooting on various situations, meaning that there is no pattern or logic on those restarts. Usually I am just casually using my LG G Flex 2 and bang, the phone restarts. I can't find any meaning at all. I have looked it up but I could not find anyone with a similar issue, nor a solution.

What makes it even more crazy is the fact that I have tried numerous factory resets, as well as installing a new ROM! (I have installed the H950PR 5.1.1 ROM over the 5.0.2 AT&T one), however the phone is still not working properly. I could swear the problem was the ROM, but it looks like it is not.

What can I do about it?! I live overseas so returning the phone to get a new one is not an option, and warranty for LG is not international :crying:

Thank you and best regards.