My connection was 900/70 (or 50) when it was first activated, it was a stuck profile on a particular port on my ONT/provision which Openreach had to correct. The upload was still provisioned at the previous connection speeds is what the OR told me, so IMO it's entirely feasible the connection could have a similar issue here..550/118 isn't a profile issue as it doesn't align with any (commonly supplied to consumers) services. If this is a new service then your Hub might need to get a firmware update over the next couple of evenings.