Do the leaves look alright on this plant, ie curled, as I don’t recall it looking like this last year, or is it being affected by the white insects on the leaves which we treated over the weekend?
That's aphid damage, probably caused by the aphids laying eggs on the underside of the leaves. You could try just blasting them off with water rather than using an insecticide.
North East Somerset - Clay soil over limestone
You can see the greenfly on it, lots of them, make up a bucket of water with a squirt of washing up liquid, hold the plant upside down and swish it around.
Gardening on the wild, windy west side of Dartmoor.