Maurice, I am in the subtropics and have several registered dormants that do not lose their foliage in winter. Most of these, however, were known not to act as dormants here (i.e. based only on the sellers not listing them as dormant). Interestingly from what you say, I am unsure if they stop growing. However. I will watch attentively this winter next year. The one I do have that dies off completely is Forestlake Ragamuffin. Alas I did not notice that it was a dormant when I bought it. This year was its first proper spring and it has regrown vigorously with 3 fans (from 1) and is into its 3rd month of excellent flowering. I do not know if this is going to continue through the years to come.
I have had several seedlings that have died back, after a few months to spring back but I am unsure yet if this was neglect or biology.
