Predator PH315-52 restarting randomly

Hi! My Predator Helios 300 PH315-52 is randomly restarting. My screen freezes, then flickers a bit, and it restarts without a blue screen. It has happened while gaming, browsing only and while doing nothing. Sometimes it goes without restarting for days, and sometimes it restarts right after I turn it on. It also tends to restart more when I open the lid after closing it (maybe it has no correlaction and I noticed it more instead).

I checked and tried everything I found on search engines (both on this forum and on other ones), but nothing worked so far. My partner has an exact same model (PH315-52) with the exact same configuration (I configured both the same way with the same driver files), but his doesn't restart. His predator is also newer than mine by a month.

Thanks!