Interesting bit of research on London prices - this website has sold prices from an auction from 28 June, few weeks ago
https://auctionhouselondon.co.uk/auction/june-28-2023/
We're currently looking in south london, a couple of flats grabbed me on that list ...
This one in Lewisham went for £352k, seemed cheap to me. Checking land reg website that flat last went for £515k back in 9/6/16.
This one in Dulwich sold couple weeks ago at £290k. Last sold 11/3/16 for £415k.
Both of those down to two thirds of their 2016 prices. I haven't gone all through the auction prices, but picture does seem to suggest lower prices.