I have found many plants are slow this year. I recorded -16 in the winter and we all have probably lost some treasures, just keep trying by doing what you are doing and just maybe you haven't lost yours.

I know how you feel. Its happening here to. But dont give up my fuchsias only have a couple of leaves on each plant but at least they are alive and kicking. I repotted mine and put them in a sunnier pot but things are happening very slowly. I am sure yours will survive

I thought some of mine had not survived the winter of -30 despite being in a frost-free place but some tiny leaves have suddenly started to appear. Others are growing strongly - one is already well in flower. The same happened with two plumbago - one is well into leaf and I was about to chuck the other when I looked closely and found it was just coming into leaf as well. So don't despair.

However, if you haven't repotted this year I wonder if you have checked for vine weevil grubs? I just repotted a couple and found grubs in there despite having treated with Provado. Though I gather that can take a couple of weeks to work. If you tug gently at the plant you may find it comes away in your hands because the dreaded weevil has devoured all the roots. (Less likely to come away if it is an older fuchsia because they have old roots which don't seem to get eaten so worth checking the compost anyway.....)

many thanks for the answers so far