Detect and save media_player source change?

Hi,

I’m using an Harmony remote for years, but my TV provider now uses an Android box for BT remote control, which controls all HDMI device with CEC…
I still want to control my TV & DVR with the harmony remote, but today it doesn’t detect when the TV is playing, and everything is unsynced.

Is there a way to detect and safe media_plater source changes?
I was looking to use such a trick to save and update the Harmony source when detected, but I see only services to change source on the media_player, no event triggered when the source.
Maybe I should set a */1 minute script to pull the soruce information is that’s possible?

Any ideas?

Thanks,