are you using the teats socket as @gg30340 suggested or still in master socket
Have you tried connecting the Smarthub into the test socket to see if things improve. It could be that you have a faulty face plate.
If there is no difference all you can do is report a fault to BT and request that an engineer be sent out to investigate the problem.
As an aside, going by the estimate checker you will not be bale to reach the maximum speed for Infinity 1 so it is a waste of money paying for Infinity 2.