Confirm it works fine with VLAN 10, also when set up with a different ISP to Mercury.

Only ISP type issue I had with them was when Quic was migrating from PPPoE to DHCP and using a dual stack.  The auto-detecting ISP settings threw a wobbly at that until Quic disabled one of the two, that was a year+ ago so may have been fixed in a later firmware, they are always updating the firmware with new features.