massive FPS drops. (cut in half). software issues related on ASUS ROG 503GE

I bought this laptop 2 months ago. the issue started 2 weeks ago..no changes were made whatsoever.so the issue is.. when Im playing a game, for like 5-10minutes. fps were constantly drop in half. example:RE2 Remake = 60fps to 20-30Spec Ops The Line =...