underlines/polish letters issues - github files vs google fonts

[ljoeljoe]

Hello Font People! I noticed strange things with Mona Sans font. I downloaded files from Google Fonts and the underline is huge and it's definitely some kind of bug. {Please have a look at the screenshots from Adobe Illustrator:

Another strange thing is that when I install fonts from github, the underline works fine, but there are no Polish characters:

Do you have any idea how to fix these isues? Thanks a lot!