Did you try a factory reset by pressing the recessed button on back and holding for 20/30 seconds until hub lights flash and see if that helps you connect your devices
Tried that a few times not good
You said the PS is directly wired (presumably to the SH2), have you tried it in all the ethernet sockets on the SH2 and tried multiple ethernet cables? Can you try anything else directly wired as a test, eg laptop?
This may seem daft, but can you check that the SH2 is issuing ip adresses - if DHCP has been turned off then it will not - the resets should have turned it on anyway if it was off but worth cecking
If everything fails to connect then it would suggest the Ethernet ports on the SH2 are suspect - try reporting it to BT and they might be able to resolve it or replace your SH2.