this happens with mine too... just rma'd my monitor PG279Q, the first one i have is 2017 batch. which i have to rma it because of dead pixel and bad ips glow, then i came straight to asus's distributor to get a replacement and have to unbox 5 brand new unit to get my replacement unit that acceptable, all the tested unit is bad , dead pixels in 4 units, terrible BLB .. then i took the one that have acceptable BLB, but when i came back home i realize that mine is having color uniformity issue, warmer/yellowish on the left side darker/blue-ish on the right side and also had a bright/stuck pixel.. this is terrible QC from asus, Those 5 monitor i've tested is december 2018 batch... No improvement since the fisrt batch which is really bad, they seems didn't learn from mistakes. this is unacceptable since it's not a cheap monitor.
I've tried to tweak the osd settings but can only make it less noticeable. not dissappear. i think im gonna rma it again at the end of 2019.