I have had this shrub for several years and it has bloomed well. Last year I had it trimmed in the fall and this year it bloomed in the Spring. In the late summer I was surprised to find that it was completely leafless…. the new growth and the older part. What should I do? It looks very strange.
I had something very similar occur on my Kerria. The symptoms you describe are part of a fungal disease called twig blight. It is characterized by rapid leaf spotting and loss of leaves. The stems will develop telltale characteristic brown lesions. You should rake up and remove all fallen leaves and cut out all infected stems. In my own case and perhaps in yours too, I had to remove all the stems down to a few inches above the soil level. Fortunately the root system is able to regrow new stems next year. It is best to keep your eye on the new growth next year and remove any signs of infected stems as they develop. You can also use a fungicide such as lime sulfur in the spring. If this does not describe the problem that you have, you could take a photo of the branches and stems of your plant and posting that on the website.