Problem changing fonts

I tried to change the default font in scrivener to the one I prefer to write in and discovered when I change it to any other font or any other size of the default, what I type vanishes. When I return to the default with the default size, it comes back.

Is anyone else having this problem?

Have you tried a few different fonts to see if perhaps it is a conflict with that particular one, or perhaps even the type of font format it is?

Could you post details of how you got it to work?
I use American english and Mint which is based on ubuntu and can’t get it to work.

thank you,