RX450Sussex

I have a 2017 RX450, and have this same issue (see picture). My local dealer says the seal cannot be replaced on its own and it requires a complete new sunroof, at a cost of £6000 including labour. The car is covered by Relax, but they deem that perished rubber is not covered. If anyone out there has managed to get theirs replaced under Relax, please can you let us all know the dealer involved, so that we can use this info to try to persuade our own local dealer(s)