Low FPS on laptop (not even stable 75) especially when taking gun fights (mouse movement) and

My Specs: ASUS TUF FX505DT AMD Ryzen 3750H Nvidia GTX 1650 32 GB ram I always play on low graphics and still I cannot get stable 100 FPS. I tried limiting fps to 75 and guess what, even I cannot get stable 75 FPS. Most FPS fluctuations are during situations like opponent running and gunning (mostly at close range) with spectre or stinger (in this case my FPS is let's say 75 suddenly it drops to something like 30-40 there are some frames skipped and next thing is me spectating someone), or util usage (especially with raze and now clove) or sudden mouse movement from my side (suppose opponent appears suddenly, fps becomes very low) or gunfights in general. I've seen this happen in training range when I start bot strafing too. I've tried everything available on internet, lowest graphic setting, using dedicated gpu in windows setting, closing all background processes etc. I won't say I'm a good player and I don't play this game too competitively, it's just if I play I want to enjoy the game instead of worrying about fps issues.