Masdevallia 'Machu Picchu' Issues

[escualida]

I've had this Masdie for about a year now, and it has been in S/H for about 10 months. It seems like it's doing alright, it's growing roots and the existing leaves it had have almost all stayed green and intact.

However, every time it starts to grow a new leaf it does well for a bit, but at a certain point it turns yellow, shrivels up and dies off. It's done this at least 5 times, there have been no new leaves that have grown fully. What's weird is that the bottom part seems to stay alive because I get new growths coming from the stumps and new roots coming from them as well.

I used to think it was because of overfertilizing but I stopped fertilizing altogether and it's still happening. See picture.



What could be going on and how can I fix it?