That sounds like the switch in the headphone jack has gotten stuck on. Most likely some sort of debris got into the port, although a mechanical failure is certainly possible. Send a private message to either @RokuDanny-R with your Ultra serial number and they can help you out.
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I tried everything and nothing worked. remote stuck in headphone mode, Here is a very simple fix that worked for me. Remote has 2 position slide switch on left hand side of remote, position towards front in for hands free remote, rear position for headphones. When you plug your head phones in switch has to be in headphone position. Headphones are now working. Most people then put the slide switch in the hands free position. Now I want to go to regular speaker sound. I pull my headphones plug out of the remote and the tv still shows headphone mode. Simple solution: slide switch is still in hands free mode. With headphones plugged in set slide switch to headphone position and remove head phones and tv will go to speaker mode.