Hi @Anonymous User
How many Freeview channels do you normally get when just using the inbuilt tuner on your TV ?
If you have split the TV aerial on both the smart box and the back of your TV, then plug the main incoming aerial into the back of the smart box and bypass the television and re scan the TV channels again.
Also check this website if there is no scheduled maintenance or weak TV transmitters or TV relays that may be effecting the number of TV channels you are currently picking up.
Sometimes a number of TV re scans on the smart box can improve the number of TV channels received.