Hello, Les.Smith4448.
Welcome to Microsoft Community!
After reading your description, it has come to my attention that the resolution of your Surface Pro 7 may have suddenly changed. To assist you in mitigating this issue, I will share the following with you:
Restore resolution to default
- Open Settings: Press Windows+I to open Settings.
- Go to System Settings: Select System.
- Select Display: Choose “Display” in the left menu.
- Adjust resolution: Select the recommended resolution in the “Display resolution” drop-down menu (usually marked as “Recommended”)
If you wish to continue to change the size of the text text, you can continue to refer to the guidelines in the link below:
Change the size of text in Windows - Microsoft Support
If none of the above methods have been able to work, as a last resort, we can try resetting the settings of this device:
Restore or reset Surface for Windows - Microsoft Support
Note that this does not completely erase your device, it just restores the various setup options to their default values. If you are concerned about any loss of information, you can also make a backup of your important content.
These are some of the suggestions I can share with you at the moment.
I look forward to your progress and am always here to support you.
Best Regards.
Leo.L - Microsoft Community Support Specialist