Upfront H1 heading NOT responsive

For the most part the theme does seem to work across devices, but for some reason the H! headers at the tops of my pages are not resizing based on the device. If the page title (i.e., H1 heading) is longer than about 5 characters, the theme doesn't seem to know how to resize it?! This is most obvious for the mobile phone size.

Here are some example pages: