Karan, thank you for your response.
I tried your solution, but for some reason, it didn't work for me. I removed the optical cable and connected the HDMI cable to the TV's HDMI (ARC) port and the soundbar's ARC port. Also,
via the SOUND settings menu, I set the Sound Out to HDMI (ARC). According to the settings display, this also automatically turned on the LG Simpliink. Unfortunately, something is amiss because I could get no sound from the sound bar.The volume buttons on the magic remote now controlled the the soundbar volume indicator (which was not the case before the connection change), but no sound was produced.
Any further suggestions?