I am experiencing the exact same problem.
I changed the potting mix because I thought it was retaining too much moisture, now the potting mix is back to what it was originally, needing watering about every 4 days (by the skewer method).
But the leaves are still soft, leathery and drooping. Wondering whether to let it go completely dry ths time ???
They are a nice dark green color, not yellowing, so, I suppose while there's color, there's hope.
I also had a new leaf that started splitting from when it was about a 1/4 inch long, why, I don't know, but it is almost at a 45 degree angle to horizontal and a bit firmer than the other leaves with the split at the end of it. Who knows ?
My phal is indoors and under the same conditions it always has been since I got it. Maybe it's sulking for some reason ?