Cytropodium macrobulbon with dead leaf tips

[jrguevar]

Hello,
I would like to have your opinions on what I've recently noticed in my new sprout of the macrobulbon. This plant has been a roller coaster of emotions to me, last year it had a beautiful bulb with nice foliage just until you inspected the roots (completely burned) link
For the ones that also speak Spanish please check the link to see the followup of this guy. Long story short, some sort of root fungus managed to get in this pot, every root that touched the medium got burned even when I tried changing the medium that touched the roots, nothing worked and I was just left with three rootless. Thought of discarding it a whole but, thank God I changed my mind and placed the naked bulbs in the shade with high humidity and in this years spring it sprouted. and last weekend I decided to transplant it again. Now Im looking at the leaf tips and are all burned and with some spots, can someone advice about what could be?...