Got a reset button?
Its debugging menu.. You can enable it or disable it via hidden menu. Search google for secret tcl android tv menu, you have to go to brightness settings and use 4 digit combination to enter secret debugging menu, there you can disable it.
Press the power button with volume down button
Update: I solved it. It was in the service menu. It was an option called Sita P mode. I turned it off and everything went back to normal! Thanks to all who recommended the service menu and all who tried to help.
Reset or call the manufacturer. If not you can send me the tv