dell alienware aw2518hf ghosting/coronas/other problems

[Slender]

Unfortunately or fortunately, I became the owner of this subject, before that I had asus vg248qe and after I tried dell I had a very double impression, first of all, I met ghosts in the low shutter mode, and the mouse movements were very late , I tried to solve the problem through the engineering menu, (overdrive item), but it was constantly reset when switching windows (games). In general, on the forum, I found out that it is possible to fix a flaw through CRU, fortunately the ghosts are almost gone, but the smoothness and previous responsiveness of the mouse disappeared, please advise what can be done with this?