Thanks a lot for the quick help, it seems to be working fine!
We have now adopted 2 of your fonts for our puzzle game, will let you know when we upload the latest version in case you want to take a look.
Thanks for your answer! We are using Godot 4.2.1. This doesn't occur with any other font we have tried so far, including one of yours that we are already trying for other types of text: https://not-jam.itch.io/not-jam-old-style-11