Black roots and dry new spikes with bulbs ( before flower opens) are

[Cristy2430]

Hi! My name is CristyZM . I live in Miami. I have a lots of dendrobium orchids attached to a palm tree for about 5-6 years and they always did fine. Recently I noticed that the new spikes where drying up before the flower will come out and that the roots where become black ( not mushy), like a black dirt on it. Wondering what I’m dealing with and what need to be done in order to get them healthy again. The leaves itself they are good.