This happens to me on occasion when I use my IPAD. The solution that I found works for me was to hit the "reload current page" button located at the top of the page on the right side of the box that contains the website address. The reload button is the clockwise semi-circular line with an arrowhead on the end of it.
Dave W - 2013 Escape 19' and 2011 Toyota FJ Cruiser
"You've got to be very careful if you don't know where you are going, because you might not get there." - Yogi Berra