As caridad said it just means it’s gone to the manual route instead of digital.
I think with digital every check is done automatically and just needs a person to accept it at the end so it’s much quicker.
I’ve heard anything as little as phoning them up can cause it to go to manual processing so there may not be any problems. Only way to be 100% though is to contact them and be sure they’re not waiting on anything on your end (as it’s already gone to manual it won’t add any time).
There’s currently about 6 weeks wait in processing depending on which office. I’m at 4 1/2 weeks in Durham and it’s not even been picked up by an examiner yet.