When I watch a video using Giant Bomb's own video player on an iPad Air I get this issue. The video runs fine for maybe 10-20 minutes, but after that it'll start looping about ten seconds over and over again. To get around this, I have to manually skip ahead a little. Usually, this fix lasts for a few minutes - then it starts looping again. Often before this happens, there are some issues with the audio sync as well - where the audio keeps going and the video freezes for a while before it speeds up to catch up with the audio.
I've had this issue on an iPad Air (1) running iOS 11, using Chrome and Safari on an ADSL2+ connection - with around 6mbps download speed.
It's quite maddening when it happens.