Dendrobium Spectabile leaves with dark sunken spots

[dickinson.mead@gmail.com]

I just got this young Dendrobium Spectabile and it looked just fine. The next day I started seeing dark sunken spots on the newest growth leaves. The spots started on the tips and moved inward. The next day the had doubled in size and also started on the next newest growth leaves. I trimmed the involved leaves and doused the edges with cinnamon. That was yesterday.... today, I see this (see images) It has started again on more leaves. I have sprayed it down with hydrogen peroxide and I don't know what else to do.