Issue with Sony Bravia control via Remote: Send Command

Hi, I’ve got two Sony Bravia TVs, one much older than the the other. The IR remotes work on both TVs for common commands, making it a PitA to use them for anything as I have them both set up side-by-side (one as a computer display and the other for video surveillance). They are both network connected and I’ve added them in Home Assistant, with both responding to Remote: Turn Off and Remote: Turn On. However, only the newer TV will listen to other commands, eg. Remote: Send Command - (PicOff).
Can anyone with an older Bravia (~2016/17) let me know if this is a limitation of the older television? I’ve tried “PicOff” and “PictureOff” as the command and though the IR remote of the older TV performs the operation on both TVs, the network command fails.
Just trying to figure this out before I resort to buying an additional IR device just for that one TV. Thanks!