How to fix thunderbolt to vga display port?
If the adapter works fine on another Mac (second bullet point) then it is not the adapter. If you have tried a number of different adapters on your Mac and all of them do not work then I would then assume that is it one of two things:


A hardware issue with your Mac. EG a bad lightning port.
An issue with the installation of macOS on your Mac.


From your description of the symptoms I am leaning towards #1. However since backing up your Mac, re-formatting the HD, reinstalling the OS and restoring your files is a free (if tedious) procedure that would eliminate whether or not it is an OS issue I would start with that.

And if that fails you likely need to take the Mac in for repair.