Hi i am a new X500 owner in the UK. Is it possible I can have the beta firmware? I too seem to experience physically connected dropouts although I can still access LAN devices when this happens just no internet access but wireless works fine when this happens.
So I think I'm experiencing the same issue here, I don't own a Xbox however.
TalkTalk VDSL router acting as a VDSL modem in Bridge Mode > X500 > CAT6 > Netgear 6 port 1GB Switch upstairs > Desktop my NIC's speed & duplex in device manager is set to 1.0 Gbps Full Duplex