Small rust color fungus on dying Phal

[rochalil]

Hello! First time in this wonderful board.
I've been searching everywhere for a solution, so far not a clear answer.
I got this beautiful mini phal from my mother and decided to repot it because it was trapped in cork.
Cut off some dead roots but overall healthy. Repotted with airy medium (mixture of sphagnum moss and coconut) in a slotted transparent plastic pot.
I keep watering every time the medium looks dry by dunking the pot for 15 min in water and then letting it completely drain.
Fast forward 2 months later and I keep seeing dead roots and tiny red fungus, at this point I have cut off almost all roots, they all rotted!
I have no idea if my Phal is going to survive, I thought I did everything right.
Can someone help a beginner?