Font size difference between machines with same theme

I’ve set up the same theme on both of my machines (gruvbox [1]) using TaskPaper 3.6.2 (290).

  1. What I’ve noticed right away is a different font size on the 2 machines. What would explain this behavior?

  2. I’ve also noticed that some elements that are bold based on the stylesheet are represented differently on the 2 machines. What could explain this?

I apologize for the vagueness of these questions.

Do the monitors of the two computers have different resolutions? Different brands?

Not sure, can you post two screenshots comparing the two?