Red Internet light on HG633 new fibre connection

Hi,

I've had my fibre internet activated and told it was now live however the Internet light on the router is staying a solid red. Line tests etc prove to be okay and talk talk have raised to a network engineer. However I think after reading some posts this may well be a network authentication problem at the exchange, previous owner had talk talk broadband but not fibre, so may well be that talk talk have not updated BT with the fact this line is now fibre and therefore not authenticating properly?

Any advice on how to get this sorted asap or any talk talk staff about to sort this please.

Thanks