Do you have an orchid show coming up? Just kidding. You see, my orchids always seem to avoid having their buds/spikes open for the shows.
Some orchids are very, very slow to open their buds and even seem to take breaks. I have a few that are in bud or are spiking and it seems to be taking forever. If this isn't the case, and the roots are healthy, changes in light and temperature can have an effect. It seems as if the temperatures are fine but perhaps the changing of the sun's angle or the shorter number of daylight hours has something to do with this. I know many of my South windows are just starting to get decent light.