DirecTV Remote Control and Sony TV

I set up my DirecTV Remote Control to work with a Sony Smart TV using the Sony codes provided by DirecTV. The match was successful, except for turning on the Sony Smart TV. However, it works to increase or decrease the TV volume and to turn off the TV. I used the same DirecTV remote control with another Sony TV—which is not a Smart TV—and it works for everything, including turning on the TV. Therefore, it seems that the new Sony Smart TVs can only be turned on using the Sony TV Remote Control and not with the DirecTV Remote Control. I have already tried using all the Sony codes provided by DirecTV, but the only way to turn on my Sony Smart TV is with the Sony Remote Control. I would appreciate your help. Thanks!