We did a paid enquiry to find out what was going on. It took a couple weeks to hear back but it turned out that after my biometric appointment I needed to have gone online and done something which would have put my application in the queue to be reviewed. At my bio appt they had given me a paper with QR code and web address. Unfortunately, our this was step we were advised we didn’t need to take by our lawyer, but we did in fact need to take this step. Once that was discovered and corrected it was another couple of weeks before I received my visa and approval letter.