Total Root Loss After Repotting

[cherrypuff]

Hi all, I recently repotted some of my grocery store phals. They were previously in tight sphagnum moss, and I repotted them into 100% Orchiata bark.

Today I decided to check the roots of one of those orchids, and to my horror, almost all of the existing root system was rotted. Even some of the existing root tips that were growing have rotted.

What is the best course of action here? Should I continue to keep this in bark? Or should I repot it into 100% sphagnum moss? Or maybe 50% moss 50% bark?

My climate have been averaging 85F/29.4C days, and 79F/26.1C nights. Watering is not an issue for me, I just want to save these orchids .