Welp, it seems that I was finally able to solve this problem. After breaking my head against a wall, the email I got from support gave me a clue: I recalled that my CPU was tweaked because it was overheating, and I performed underclocking via BIOS. The voltage was reduced by 0.14, which considerably lowered the temperature (summers are quite agressive here) without producing trottling nor any other problems... until now.
After messing with it for a while I left it at 0.10 and for now it's working fine. I will let you know if anything else changes!

Many thanks for the help.