Windows 10: Monitor screen look horrible at 75Hz, but smooth in 59Hz

Hi everyone,I'm using laptop ASUS TUF F15 2021 and extend monitor LG 24MP59G through HDMI cable. But when I setting my monitor is 75Hz, everything looks very horrible,like this: But when I setting to 59Hz, everything looks smooth.How can I fix it?Thanks.

:)

 

2 monitors - one 75hz, second 60hz. Refresh rate problem.

1) Windows 10 Home version: 1709 current build: 16299.125

2) When this happen my monitor's OSD still shows 75hz but I can see it isn't 75hz. Screen looks very laggy and when I stop or minimize video on second screen, first screen immediately goes back to 75hz.

3) No. I haven't.

I tried reinstaling the graphics driver but it didn't help.

 

Second monitor screen resolution problem

Hi,

For us to properly isolate the issue with your second monitor screen resolution, we would like to know the following:

• 
  Were there any changes made on your computer prior to the issue (e.g., updates, software installation)?
  
• 
  When did the issue first begin?
  
• 
  To make sure that we have not missed on anything, what troubleshooting steps have you done so far?
  

In the meantime, we suggest that you try resetting your monitor settings, and check if the issue still persists. You may refer to your monitor on how to reset it.

We look forward to your response.

 

How to get computer to 75hz but computer isn't letting me choose 75hz, stuck at 60hz

Hi, I just bought an Acer desktop and a LG monitor. The monitor has specs of 75hz but when I try to choose the settings to 75hz it only gives me the option of 60hz. But the thing is that I forgot how to get back to where it gives me the option to choose
the refersh rate! So can someone please help me? Thanks!