medinilla problems

[maxima]

this is my third medinilla and i'm having the same problems i had with the previous ones (which eventually killed them both). it looks like some kind of fungal disease but i have no idea what i'm talking about really.
i know it wants humidity but can low humidity really do this to a plant ? i mean none of my nepenthes went through this.

can any experts help out ? i really want to save this plant.

 

[maxima]

To my surprise this one has recently bloomed (not a magnificent one though) and it still looks miserable.
I've tried skim milk + water and rubbing alcohol to no avail...Anyone has suggestions ?