Hello dead0830,
Thank you for using the Apple Support Communities. As I understand it, certain areas of your trackpad don't seem to consistently respond.
Does this happen always, or do those areas of the trackpad seem to sometimes respond?
Does it help if you click Apple menu () > Restart and test again?
A good starting point is to check to make sure the trackpad is clean, covered in the resource titled If your pointer is jumpy when you use a trackpad, Magic Trackpad, or Magic Mouse:
Moisture collecting on the touch surface can also cause this issue. Wiping off the surface of the trackpad or mouse with a cloth or tissue usually fixes this.
If the issue goes away when you put a piece of paper between your finger and the touch surface, consider purchasing a Teflon applique to fit over the surface to prevent moisture from having direct contact with the touch surface. Before you install the Teflon applique, make sure the touch surface is clean and dry.
Note that oil or lotion can also cause the same issue. You can clean your device's touch surface with a lint-free cloth lightly moistened with water."
If not, you might try the steps below in order to narrow things down. These tests will help you to rule out certain causes for software issues, and to determine if the issue is system-wide or user-specific:
Use safe mode to isolate issues with your Mac
How to test an issue in another user account on your Mac
Feel free to reply back with the results of testing, and the community might be able to offer further assistance.
Take care.