2020 Ultra connected to Sony 2020 77” OLED and Yamaha YSP-5600 soundbar.
Ultra connected to SONY HDMI input.
Yamaha connected to Sony EARC/ARC.
Sony TV remote powers on and off all three.
Ultra remote turns on all three. But power off leaves the Yamaha on.
This was not a problem with TV before Sony (also 2020) or with 2019 Ultra.