Any suggestions for why this may be? When turning on the system, the TV defaults on to 3D mode.

Receiver is a ARCAM AVR600
Source is a Xbox One
Media is not 3D

That's a feature....

Ha, I hope not. This is a new behavior.

Disconnect everything from the TV and test by itself. Then add one device at a time directly to the TV until you narrow down the culprit. My guess is it's the Xbox settings.

Mine does this as well and I don't know why.

Receiver: Yamaha RXV2065
Cable: Cisco HD box

It doesn't do it when I'm using the Roku or AppleTV...only the cable box. All components are going through the receiver. It happens intermittently enough that I don't want to try going through the TV itself to see if somehow the video switching on the receiver is triggering it. Being that it happens with cable only, I doubt it has anything to do with the receiver.

I have a client who was having the same problem. Like punter only would happen when the cable box was selected, other sources played fine. I fixed it by going into the tv menu and then to 3d. I forget what the exact setting was but once I turned it off the problem stopped. Hope this helps.

I forget what the exact setting was but once I turned it off the problem stopped. Hope this helps.

Over the weekend, did this magical setting that fixed it come back to you?

Nothing came to me over the weekend but I took a look through the e-manual. The 3d auto view option is what I believe I turned off. In my case the customer had no desire to watch 3d so turning this off was no problem. But if your customer does want to use 3d you will have to add functionality to your remote system to turn the 3d on and off manually. Hope this helps.

Roger that - thanks!!