Usually, this problem is relevant to Revolution Slider. You go to the slider editor. You click the CSS Global button. On the popup, you will see the link of google font.
With the new Revolution Slider version, you click the Edit Depricated Global Styles button on popup. It will open the second popup. You will see the code in there. If you don't see the code, you hit Ctrl + A (select all). You will see the code. You copy all code in the second popup and empty it. Then, you paste the code to the first popup, edit and save it.