I've been having the same issue, across my two iphone XR's. I don't have an ipad to try. I down graded to an earlier version of 5 and it seemed to help, but then it auto updated yesterday to the most recent version, and it seems the problem still exists, but doesn't always present itself. I also hav...

I was experiencing similar issues, eventually I figured out that BI only plays well with 264 encoding. 265 or + variations didn't work well, and then after a couple minutes the amount of lag from the image was more than 30 seconds. Might check to make sure they're using 264.