Issue with sound/wonky acting TV

[fighthefutureofhd]

I don't know where to post this, so I hope this is the right spot. Here's the thing: My TV has gone all wonky with the sound inputs. I recently bought a new Hisense 100" 4K tv last November. Everything was fine until 2 weeks ago when the TV went all wonky. For some reason it kicked out of the setting I had for the sound to be through HDMI auto. I have a receiver and a 7.1 surround sound speaker system (with speakers in the ceiling). Now, the receiver and sound still work with TV. The problem is I cannot select HDMI auto at all in my sound input selections, which is where the wonky part comes in. If I want to watch anything through my TV and not my 4K player I have to have the TV speakers on. When I do that it creates an echo type sound whenever I play anything through my 4K player and receiver. I reset everything back to factory settings, but that didn't fix anything. And only made the TV act even wonkier, as I'm having to readjust the display settings almost every time I watch something. I need to figure this out seeing as it's frustrating to say the least. Thank you all for any help in this.

[oddbox83]

Have you recently connected any new HDMI devices anywhere in the chain?

I have a Humax PVR which utterly ruined my HDMI ARC link from TV to receiver. Drove me barmy and I blamed the TV for ages. I eventually pinpointed the Humax box as the culprit and I had to plug a special HDMI adapter into the Humax to stop it sending garbage on the CEC pin, which it would do even when just in standby. HDMI audio worked perfect again after that.

[fighthefutureofhd]

No, I have not. Nothing's been changed or touched.