I just got one of these myself and have noticed the same leaf wrinkling you described! I too have been letting it dry out. im glad I looked at this because i was at a loss. I thought i was watering it right...
I've been very diligent in watering mine in the past few weeks and the leaves have fattened up now. They feel firm to touch as well.
The new lead is maturing much smaller than the previous ones, but this is the one that got hit by the "drought" lol
I see roots are going crazy and there is also another new growth developing. yay!!!