I've just started this and I'm suprised not to see more comments on 3D, which is indicated as 6,8,9 but the bars in the grid (never mind the fact that 13A doesn't highlight so maybe it won't even let me enter anything) make it look like 21A is (8,1).
So, something is wrong - and if it's deliberate (and yet, the smart folk here have figured it out), then I'd say it's unfair. However, as someone else said, this is the Grauniad, I guess it's not.
I'll assume it really is 6,8,9 unless a kind soul can drop a hint.
Thank you.