Huge fps drop

I don't know how bad the game is optimized but i'm currently playing with a GTX 1080 8GB, intel core i7-4790K, i'm having between 80-100 fps in game sometimes a bit lower but since 3 days i'm having random huge fps drop, it goes from 80 to 10 fps constantly and this can last for over 2 min before the game fps goes to "normal". I don't download/upload nor using other game programs, only steam, geforce experience, GOG Galaxy, Chrome launched.
If anyone got this issues i'm glad to read them.