You do not have to turn of CEC, just turn of the CEC auto power and Input option.
Below is the article that contains the full instructions.[Link: support.myharmony.com]
Press the Home Button
Navigate to the bottom page and select settings.
Select External Inputs
Select Bravia sync Settings
Set the below settings to OFF
Set Auto Power to OFF
Set Auto Input change (MHL) to OFF
Set TV auto Power On to OFF