I have an 82" Q90 from 2019 that recently started displaying this one box connection error. I have tried all reset options including a factory reset from the hidden service menu. I have replaced the one box, the one box cable, and the motherboard behind the screen. The app menu briefly appears at start up and if I select an app I can watch as normal. If I let the app menu time out, I am stuck at this error screen. The only remote button that will bring the TV back is the dedicated Hulu button, all other buttons are unresponsive except the power button. Any help is appreciated before I retire this TV. Thanks, Paul
