Well see Apple doesn't sell 1440p external monitors, so the answer is you should stop using that trash and move to one that brute forces the sharpness problem and costs way too much because it has an Apple logo on it
Cute, but irrelevant. I just searched Amazon for "4k monitor 27 inch" and there are any number of highly rated screens from recognizable brands for around $200.
You don't have to splurge to get a 2160p monitor that a Mac will love.
Those monitors kind of suck. You can only get $200 if it's a crappy VA panel at 60hz. My 1440p monitor is a lot better, but apparently not supported by Mac for ideal rendering.
https://www.walmart.com/ip/Apple-27-inch-Monitor-2560-x-1440...