Hi @Anonymous User
If your smart box upstairs is also connected to a TV aerial, have you tried temporary connecting the box to the upstairs TV aerial and re scan the TV channels on the box in question.
When you factory reset the box did you press the small reset button on the bottom of the smart box which is a soft reboot or did you go into the box menu settings and did a full blown factory reset.
Sometimes with the smart box inbuilt tuner which is not the most sensitive tuner when you lose channels you need to re scan a few times.
Also there is the possibility that the smart box TV tuner has developed an inherent fault.
