Wrinkled, squishy phal leaves

[butterfly_muse]

Good evening, everyone!

I come to you with a slight problem with my mounted guys. I have two phals (one regular sized and one "mini" which is actually bigger than most minis, lol) that live together on a piece of cork bark. Recently, I have noticed that a small leaf on the normal sized phal has gotten discolored (lighter yellow) and is squishy and wrinkly. The largest leaf on my mini phal is also wrinkled, but not discolored.

I am apt to assume that this is a moisture problem (???) mainly because the humidity in our house has dropped since we were a part of the polar vortex last week and our heat was running basically nonstop for several days. I misted them several times a day, but I don't know if this helped. My agrometer is reading 50% right now, and since they're mounted, I know they're more prone to drying out. I have only been watering them once a day, should I maybe do it twice?

And is this just water related, or is there something else? Will the leaves ever un-wrinkle? Or will they fall off? Help! Thanks!