Hi!
I had the same problems including "robot" voices or noises when watching TV (via hdmi - with setup box). Via coax cable ou using youtube app/netxflix app etc the problem did nor appear.
I solved the problem changing the setup box from the internet/tv provider. A month has passed and the problem desapeared
Today, my firmware updated to v05.60.25. let's see if you have any luck!
Best regards from Portugal