Number "3" is offset when compared to other numbers

Hi there, I have an issue which I was unable to track down successfully, and it might not even be due to this template.
Regardless, given that I'm not sure where to even ask the question, I'm starting here.

My problem is remarkably simple: When using the number "3" in the institutes for one of the authors, the number is larger when compared to the others for no reason.
Here's an image showing exactly that:

Any idea on why this might be?
Is it something to do with the font? Because I don't want to change the font, I quite like this one.