Home Office ****ed up my application. I had requested my date of entry to be 5 December. My vignette had it as 5 November. So had to haul ass, pack up, sell up, resign and get to the UK within a few weeks instead of a couple of months (needless to say my employer wasn’t happy with the 2 week’s notice I gave). Immigration agent we used at the time said I had 30 days to get to the UK and get my BRP so didn’t dally: landed in the UK on 5 November, so had the full 30 days. Walked into the post office in Tooting (random) and collected my BRP a couple of days after landing.
And yeah, they extended the collection window because of COVID.