3. Tried other HDMI devices in all ports and no issues
I am at a loss at the momment the only thing I can now think of is faulty TV box anyone else any other ideas I can try, because trying to get get through to customer services is getting silly at the momment due to the unfortunate restrictions due to the pandemic.
I see, in this case I would suggest following the process that @kizi has posted above, if you're still having issues with it set to 1080p then give it a try on 720p.
One thing I will add is that when doing this, make sure you only have one setting ticked at a time rather than multiple options so if changing it, remove the tick from the ones that you're changing it from.
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