Wa77a

I have an LG C1 55 connected to a Denon x2100w AVR on HDMI 2 (arc)... It always worked perfectly... After the latest TV upgrade I can't get anymore TV audio on the AVR. I tried disconnecting and reconnecting everything, unplugging stuff for minutes, switching multiple hdmi sources... The AVR can send data to the TV, but it doesn't see TV audio signal. All the HDMI audio settings on the TV are greyed out and disabled. Next thing I'll try to reset to factory defaults, but I suspect it won't fix anything... Note this worked flawlessly for 2 years. Ideas are welcome.