Ok, so indeed after days of testing this was not solved for me. It was acting strange, for example sometimes in dark scenes it will boot the background effect.
Until I have a bit more free time to find a proper solution, this is my workaround (Very specific for Hassio users, but might be useful for somebody)
I added the SSH keys so Hassio could execute a shell command without a password in the RPi running Hyperion, and then I added this in my configuration file:
switch:
- platform: command_line
switches:
hyperion:
command_on: "ssh -i /root/.ssh/id_rsa -o StrictHostKeyChecking=no pi@your.ip.address 'sudo systemctl start hyperiond@root.service'"
command_off: "ssh -i /root/.ssh/id_rsa -o StrictHostKeyChecking=no pi@your.ip.address 'sudo systemctl stop hyperiond@root.service'"
Then I'll have this new switch
And I automated turning on and off when the TV is ON