Anyone know how long mortgage offers are taking?

[Itsrainingten]

So we saw a house we love. We weren't under offer ourselves so couldn't put an offer on it and another buyer did. That was almost a month ago. It's still showing on RM as available so I called the agent who said the seller doesn't want to mark it as under offer until their buyer has a mortgage offer. Shouldn't that have happened by now? Does this mean there's a good chance the buyer might not be able to proceed?

We have just had our mortgage approved within 4 days. Applied last Friday afternoon and was approved this morning. We had been told by our broker that it could take up to 6 weeks though, but we were lucky that the mortgage company didn't need to come back to us asking for any more documents

Big wait for surveys/physical valuations at the moment in some areas
It was 3 weeks here last month

Ours took about 2 weeks, but part of that delayed due to us needing to submit more recent savings statements.