Sometimes, my UIWebView will have a grey box over part or all of the content. I can\'t make heads or tails of why it\'s happening. It happens regularly for certain content.
I have been dealing with this glitch as well, and have opened a bug report at apple. I would have commented above, but I don't have the 50 rep yet.
For anyone else encountering this glitch, send them a report, I included a full project demonstrating it, with a few screenshots from another app I am working on. The more bug reports they get on a topic, the more likely they are to address it, apparently.
https://bugreport.apple.com/