I used to be able to get into the Service Menu of my TCL 55P607 Smart TV using the Method(for WiFi Models) shown in this link:
https://factory-reset.com/wiki/TCL_Service_Menu

It always worked perfectly but after a recent Firmware Update to Software Version 8.10 Build 4139-30, I can no longer access the Service Menu.

Does anyone know how I can back into this TCL TV Service Menu?

Any Help would be greatly appreciated!!