Sorry for digging up this post, this is the first one that shows up on google.
I had this exact same issue but I didn't want to change my screen's scaling, so I found out how to disable it for a specific app.
If you right click on the shortcut for 0 A.D. and click go to Proprieties > Compatibility. There at the bottom you will have something like "Change high DPI settings" you should have an option at the bottom of the screen that shows up after to override the windows settings click on the checkbox and then select "application" on the drop down menu. Click OK > Apply > OK and restart the game, should have proper text now
(not sure if the names of the settings are these exact ones, my windows is not in English).