If it is the matter of iPhone, you can try to have a software update on your iPhone. Or you can fix the iOS system by the iPhone recovery tool, which can resolve 50+ iOS issues. While if it is the matter of TV, then you can ask related professionals for help.
Cannot play mp3 from phone to smart TV
in LG webOS Smart TV App Questions
Posted
If it is the matter of iPhone, you can try to have a software update on your iPhone. Or you can fix the iOS system by the iPhone recovery tool, which can resolve 50+ iOS issues. While if it is the matter of TV, then you can ask related professionals for help.