MacBook Pro not filling entire screen on External Monitor

Ben88mac wrote:

--> MacBook Pro (13-inch, 2017, Two Thunderbolt 3 ports) 2.3 GHz Intel Core i5 8 GB 2133 MHz LPDDR3

Having trouble understanding why my new LG 32UL750-W monitor (3840x2160) has a black border around the edge of the screen (underscanning?). I am connecting the device to my laptop using the USB-C port and cable supplied by LG.

I have tried fiddling with the resolution, mirroring, and aspect ration (on the monitor) but all this does is make the text tiny without actually filling the entire monitor display.

Is it possible to fix this somehow?

I am not adept with run tools, however any help or suggestions appreciated.

Try using Extended Desktop Mode instead of Mirror Display Mode. Mirror display also mirrors the display resolution. Extended desktop mode allows you to select the native resolution of the external display

>System Preferences>Displays

Get help with video issues on external displays connected to your Mac - Apple Support
 https://support.apple.com/en-us/HT201177

Use external monitors with your Mac - Apple Support

https://support.apple.com/en-us/HT202351

About overscan and underscan on your Mac, Apple TV, or other display

https://support.apple.com/en-us/HT202763

Hi, I have the same issue. Unfortunately cannot find an answer either. It happens occasionally with my Mac Pro 2017 and normally a few jangly resets will fix the issue, but it's being stubborn now. I don't have an LG external display, I have acer so it's definitely a Mac problem. Tried resetting the EDID, SMC, all sorts but no joy. Added pictures for context to see if its the same kind of issue.