Same issue here. Massive drops in frame-rate in general, but times where the frames will drop even more and cause the game to lag. Game ran perfectly fine for me prior to Beyond Light. Hardware and DXDIAG for my system are irrelevant as anyone can see running through these replies that even people with extremely high-end hardware are having these issues. So obviously, it's not a hardware problem - it's the software, i.e. the game engine is busted.