I am in contact with the supplier they gave me a few tips, like turn wifi etc off.Have you set the aerials horizontal?
Is the ceiling clad with plasterboard with foil backing?
Did you buy the Powermid extension "eye" that sticks to the Sky Digibox front panel?
Its not a ceiling material issue, as I have tried it at a door way, the transmitter & receive both acknowledge the signal, the Sky box only responds intermittently.
If I thought the extension eye would sort it I would get one.
This is what I have replied to them.
Tried switching things off, made no difference, sometimes it will work then it wont.
Tried just controlling the TV with the TV remote, that works all the time.
So its an issue with Sky, this is a new installation & I have 2 Sky remote controls so that is not the issue.