Every Monday I lose connection

[#1]

I assume the username is ignored - not every ISP authenticates using a username. The username is probably just left over from the previous connection/owner.

The assumption in the thread has been that it is a TalkTalk retail connection, but it is more likely a TalkTalk reseller using their business network. Different authentication may be in use.

It appears that Unihomes use Shell Internet, Pine Media, and Virgin Media as broadband providers. None of them obviously use TalkTalk Business, but it is quite possible there is another ISP being used too.

I still think that the ISP & connection is a side-issue. The real issue is whether the weekly drops are a fault or normal operation - I vote with normal operation.

[#2]

Without further concrete information from the OP we are all guessing, but I still find it strange. My understanding is that the Hub2 is only usable on BT/EE/Plusnet connections.

Thanks for the information with regard to the BB providers Unihomes uses.