@manyakrifat I blame the update as youtube kids app still works fine. No solution, reinstalling doesnt help, cast from android phone to tv works only as a sound with no picture, even then this only works sometimes. Whats your webos version?
LG55UG870 3D 4K TV, webos 2, tv software version 04.05.85, YouTube update on 16 March 2020 to app version 1.0.70 made it unusable as it just load black screen.
What is going on?
Try standalone Skype camera, works great for me, rings even tv is off so no missed calls.
http://www.androydz.com/wp-content/uploads/2013/03/skype-tv-4.jpg