You've had some really good advice above.
My
worth..
I have a couple Phals in mostly spaghum moss. But I have learn't to maake sure that the sphag is not tightly packed. From your photo yours looks pretty dense and very wet.
I used to have roots rot my plants, what I did was
1. make holes all over the pot (see photo)
2. put a layer of leca on the bottom
3. Use a skewer as moss may look dry on top but skewer may be v damp.
4.Always water by immersing the pot into the water rather than pouring from above as in my experience it compacts the moss.
If needs be and moss looks like yours I take it out & squeeze it and repot 'fluffing' the moss up disturbing the roots as little as possible.
here is a qick pic of one of mine I just took.
Hope this helps. Good luck and keep us posted