Budget import FBDI file macro works sporadically

Summary:

We import our budget from 3rd party app on a regular basis via the FBDI macro, but for one of my teammates it works sometimes and doesn't work others.

Content (please ensure you mask any confidential information):

My teammate can manually run the macro through the VBA editor, but clicking the button doesn't run the macro sometimes. Other times it works fine. I believe there must be something not loading in correctly on Excel startup, but we don't know what that could be. Does anyone have any ideas? We've logged an SR but Oracle Support keeps punting to our IT help desk, who don't really understand macros nor the nature of the VBA code. My teammate has not changed any excel settings or any other items between when it works and when it doesn't work.