I have been having this same issue for several months and can't figure out how to fix it. I checked in preferences but no luck there.
The issue is that the window is zoomed in so far there is no scroll bar. There is no way to scroll through the list of fonts. The only thing I've found that works is to use the down arrow on my keyboard. This makes it very difficult to search for or select different fonts.
I thought it may be a software issue but this has been happening for me over several versions.