how were you controlling volume?
over IR or HDMI.
what are you using for speakers, and how is it connected?
tv speakers
av receiver - aTV connected to TV, and pass-throuh to receiver
av receiver -aTV connected to receiver and pass-through to TV
Try unplugging and replugging Both ends of the HDMI cable, sometimes that clears it up
in the settings app, go to remotes and devices,
under home theater control, what does it say by volume?