That is rather strange. About a year ago we had a similar problem on our site but it was just certain members as others with the very same devices had no problems at all. And no desktop had a problem, just as seems to be the case here. I don't recall what the problem was on our site, but it wasn't a problem with the site at all. However I never did learn why some people using the same devices and trouble and others didn't. It all went away in about three weeks.
Ron