Hello, I'm TV Tech1 and I'll be working with you to identify and help you resolve your problem.
That looks like it's MORE designed for the UHD TV sets, like the 9000 and S9 series. The UH8500 series isn't mentioned as being part of that series. So WHO told you it's compatible, or what site lists it??
I just found this -
Is it possible the model is different? Did you buy this in the UK, because that's where I saw this? We have to be sure of the model and the country it was purchased at.
Ok, there IS a firmware update dated AUG 2014 for your model. We should always start with downloading the updates and applying it to your TV using a USB stick. For now, you want to disconnect the box so it doesn't interfere with the update. Look near the Download section of this page for that update, along with the instructions next to it. Follow the instructions.
Decided to stay home & try to get this sorted.
I switched off my internet & that has solved the issue. (for now) Once the internet was off my TV stayed on allowing me to disconnect the internet from the TV. I then turned my internet back on & setup a new connection to the TV. I also checked the software & is was up to date as auto update was enabled.
So to conclude I think the problem was being caused by my internet connection & all seems to be working fine.
I now need to catch the wife & kids up and assure them they are more important than the TV!!! :-)
Thanks for your help.