Itv player is working perfectly for me, was watching Corrie yesterday, no problem.
I find 4od on my iPad temperamental, when it gets to adverts I sometimes have a black screen with click for more info on it, and have to switch VPN on and off again, refresh and start again, really annoying.
I have problems with all the iplayers with google chrome, can operate any of the pause, volume etc buttons while on full screen, but fine with Firefox.
Try changing your browser and see if it helps.