I have a dialog box in my 2D game implemented using a RichTextLabel with a custom font (Vormgevers at 16px).
My game has an internal resolution of 432x243 (Project > Project Settings... > General > Display > Window > Size > Width / Height).
For some reason, sometimes letters in the dialog won't be displayed (the "i" in "in" is missing):

Even though they show correctly in the editor:

I also noticed that if I enter a space before the missing letter it shows up after the space:

I've tested the font and it works perfectly at this size on GIMP, so I'm guessing this issue has to do with the rendering the font in a small resolution...
Does anyone have any idea what I can I do to fix this? Thank you.