Certain websites load with question marks in black diamonds and other symbols. Happens in other browsers, websites open properly on other devices.

For several weeks now, certain websites load with symbols only (question mark in black diamonds and random letters). I have cleared history, cache and cookies and nothing has worked. When I rebooted computer today and tried the websites, they all showed up normally for a little bit but shortly after opened up again with the weird symbols. It is not most websites. The ones that it does happen to include spartan.com, groupspaces.com, coralvillepubliclibrary.org. The same happens if I open in internet explorer (although symbols look slightly different).