I have installed your theme and I noticed that when there are multiple categories in a post with long names the display of them is problematic.
The reason is the font-size: 0 rule that you defined for the post categories. I know that you wanted to hide the “,” character but that should be done programmatically and not via styling as it breaks the rendering of the text.
Attached you will find the screenshot with a problematic case.
Changing this without causing issues for many sites that use it isn’t easy.
Could you send a link so we can look at your case and try to help find a fix?