servere client-server desync or poor PC performance

i'd have to reinstall over and over agin till the hit reg going to the right way.  i use to aim good at this game ,but i feel that this season i can't control my mouse as i want to . some issues  wont let me control my mouse  easly like last season before.  or sometimes that i could be should that i hited at the traget but no hit reg .

this makies my performance extremely inconsisten , i play really well  when there are fewer cheaters . yet sometimes my shot completely fail to register this is clearly abnormal as i always use the exact same aiming way .

i have no idea what's causing the issue. i initially thought  it was my GPU problem  so i  sold my 7900xt  and bought an rtx 5080 which cose me 1000 dollars unfortunately the problem still hasn't been fully fixed.  i've tried  just about everthing to resove this,by  updating windows , graphics drivers and bios disabling Resize bar and many other tweaks . 

None of these  efforts have worked i've spent a lot of time and money on this game , so  i would really appreciate your help.