Screen problem

This is almost certainly a hardware problem. Either the screen itself or the cable that connects the computer main board to the screen.

You need to have your mac looked at by an authorized repair shop.

You paid a lot for your mac, you should learn how to use it, it won't bite.

If you want share your screenshot then use the image insertion button

second from the right on the toolbar at the bottom of a reply window

here.

If the problem does not show up in the screenshot then it is not software related, but more likely to be hardware related.

A failing graphics card, or broken cable between the logic board and screen or broken screen.

Can you use your phone to take a picture of your macs screen showing the fault and post it back here as I have described above.

But more than likely you will need to have an Apple Authorised Service Provider to have a look and give you a quote.

Can you post a screenshot of the affected area? Use command-shift-4 and drag to select a rectangle, as a shot of the whole screen would be too large to post here.

Also: Please run Etrecheck and post its full report here.

Use the “additional text” button and paste the report into the text box.

Press Command-Shift-4; the cursor shape will change. Click and drag a rectangle around the area of the screen that has the problem. Release the mouse button.

A file with a name that starts with “Screenshot” or similar will appear in your desktop.

Double-click to open.

See if the image in the file also includes the “glitch” or not.

It is Command-Shift-4, not Command-Shift-F4.

All macs can do this.

All macs running Mojave or Catalina have the Screenshot app

in your Applications> Utilities folder.

If you take a screenshot with command-shift 3, do these glitches also appear in the screenshot?

You said you took a screenshot earlier in reply to Luis.

And he also told you how to do it.

I said exactly the same thing in my earlier post.