Macbook pro Touchbar underscaning external display depending on USB-C port

rogerGros wrote:

The solution was to restart the Macbook on safe mode. The external display automatically got the right resolution. After that I booted the laptop and the issue was fixed.

Thanks for your support.

Good computing rogerGros !

rogerGros wrote:

I'm trying to connect a 23,8 inches external monitor to my Macbook Pro with touchbar.

When I try to connect the screen to any of the right USB-C ports I get black bezels (In red on the attached image) on the screen.

https://discussions.apple.com/content/attachment/ba10f494-8e63-4121-b147-e24d1de6f01e

If I connect the screen to the right USB-C ports I get a full screen resolution (No black box)

https://discussions.apple.com/content/attachment/9cae06c6-a0ba-4e7f-b0ac-37dbee3b8903

I've tried reseting SMC and NVRAM but notting seems to work.

¿Any idea about how to resolve this?

You do not say what exact Mac /model /year /size /retina /touchbar is this ?

2016 and 2017 models of the 13-inch MacBook Pro with Touch Bar, limit full speeds to the two left-side Thunderbolt 3 ports, with reduced bandwidth on the right-side ports.

rogerGros wrote:

It's a MacBook Pro Touchbar (13-inch, 2018, Four Thunderbolt 3 Ports) / 2,3 GHz Intel Core i5 / 16 GB 2133 MHz LPDDR3

The thing is that doesn't seem to be a hardware limitation. One of my work colleagues has the same mac model with exactly the same display connected to a left port and it's working properly. I've also tried connecting his display to my mac and the behavior is the same than the described on the first post.

Try resetting NVRAM/PRAM http://support.apple.com/kb/ht1379