Hello James, thanks for posting! I am sorry to hear of this behavior and I will be happy to help.
If possible to try, does the same issue occur if you connect to another monitor? Understood if that is not possible to test.
Pending that information can you let us now the version of MacOS you are running and the specific graphic configuration for your MacBook Pro (are you using one with only Intel graphics or does it also have a discreet Nvidia card)? If unknown, please follow these steps to generate a System Report:
- Choose the Apple Menu -> About This Mac.
- From the window that appears, click on the ‘System Report’ button.
- A System Information window will appear. From the application menu bar, click on File -> Save… to save the information to a file.
- Attach the saved file to an email to our direct support email address at firstname.lastname@example.org with ‘Ticket Number 212526’ in the subject line
We’ll examine the report and determine next steps from there.