They do shed old foliage - not sure if that's what's happening with yours - is it occurring on older growths only? I don't mist mine, other than spritzing keiki roots on occasion - it can be quite dry here in summer, and the spritzing doesn't actually seem to do me any good
From my experience, and what I have read, it isn't so much a dry period, but cooler temps in fall, winter that are needed for blooming, tho drier than summer - just keep mine from drying out entirely. Likes a fair amount of water in summer (again, can be quite dry here in summer)
After struggling with mine, trying to grow it in coconut husk chips, I changed to a mix of pumice and perlite, being as King said, primarily a lithophyte, and it's really done well for me that way.
Is this plant growing where it is in the pic? If so, it could be reaching for the light (looks spindly to me, but kingis can have a fair amount of variation, so it might be normal for yours - idk)
If you are able, you might try growing it outdoors as much as possible - mine has done very well outside - I realize you can't have it out all year, but it's good til night temps are down in the 30s F