Rootless Phal putting out leaves instead or roots

[HuniGems182]

I have a phal that had a bad mold issue, killed off most the roots, I remedied it and it remains with 1 tiny root, one knub, and a half alive half dead root.
I placed it in a soda bottle style terrarium with some water on the bottom, phal sits on rocks. Hoping for it to grow roots, since the roots left are barely half an inch..
I waited, and about 3 weeks later no new nubs starting whatsoever. A bottom leaf is yellowing, and peaking thru the top I noticed a baby leaf down in the crown. How is it going to sustain the new leaf plus the 4 it has now. All still healthy looking, but I am very nervous of them becoming floppy. Any advice? Why is it putting out a leaf instead of roots.