Superhub 2 plus Airport Extreme 6th gen... problem

Hi guys

I was using virgin super hub 2 for few months now with no problems, hub in bridge mode connecter to AE setup in seconds all working fine until one day when I lost internet connections. Airport have IP DNS and all in "Internet" tab "Network" tab set to DHCP and NAT but no internet ... no one was changing setting in Airport utility so after few hours I have to put Superb back to router mode and change "network" tab to Off (bridge mode) and then I was able to get internet back...

can you guys help me with this problem because Im still can not make this to work when super hub is in bridge mode ...

thanks for any help