It is most likely the soil breaking down. As I have mentioned in the post, they are both due to be repotted and cleaned up. The leaves are not shrivelled. I lost a whole raft of lower leaves as the flowers wound down, after I received it 4 years ago. The media was crappy and lots of lost roots! I have it in a Phal mix from RePotMe.com. The clay pot is original. I am upgrading it to a RePotMe slotted clear pot. It has increased leaves by a great deal, and is actively growing new roots. I must stress that I grow my orchids windowsill, So this time of year they are still struggling to survive in very low humidity which is due to central heating. As soon as day temps rise high enough they will get open windows and outside moist humidity. I spritz but it is a temp fix in MN winters. I have to drop my winter overnight temp this fall so I can hopefully get it to bloom. I also could just move it upstairs daily every night (Old Victorian Farm House has NO upstairs heat) I have successfully gotten Epiphyllums to bloom by wintering them upstairs. Temps drop to 50°F in Jan. I sleep up there so am really sure about the upstairs micro climate! In Summer, it is very warm and has a major over night temp drop since windows are open 24/7. Humidity is high when windows are open as well.
By the way, thanks for the pic of your gorgeous blooms! Neither of these orchids were in the proper media and they were over watered by the store personnel! My sister did her best to let it dry up a tad before Christmas arrived! She, like me, look at them like “Shelter” cat rescues! Their past is a mystery, they most likely had a tough go, being forced to have holiday blooms and being shipped and sold in retail stores by employees that know NOTHING about orchids! Actually these two are survivors that just need me to work a tad harder on their winter care! I am going to run a humidifier with distilled water near them next winter. In Summer, the same humidifier will run with a fan to cool Phrags during heat spells. It is a plan anyway!