Brassavola Dropping Leaves...
 

To anyone that may be of help. I have recently gotten into raising
orchids, and have had pretty good luck so far, with a few different
families. I recently about 2 mo ago purchased a brassavola, and it has
dropped a couple of leaves. I was wondering if this was normal in
winter, as it is with some dendrobiums, or if I should be looking for
problems. It looks healthy otherwise...

What could this be symptomatic of?

Any help will be greatly appreciated... TIA