Maxillaria tenuifolia problems

[dpm2010]

Greetings. Ive been growing this species in south Louisiana for 4 years and have had great success. I recently repotted it and need some help with identifying the problems. The plant has been successfully grown in sphagnum since I acquired it. (I read somewhere that was a good choice for potting medium but AOS tells me otherwise). The orchid gets morning sun and is shaded by the afternoon. It has flowered profusely year after year. I winter the orchid in my Orchidarium. Ive seen the plant growing in somewhat harsh conditions in Belize. Spectacular display of a species! Please take a look at the photos and share your knowledge. I don't want to lose my coconut orchid!