Phal leaf yellow and brown or 'bumpy'

[kkavanagh0]

Hi

I've attached pictures of 2 plants that I'm concered about. One has a big yellow spot on the leaf which has since turned black in the middle. It also had bud drop of tiny buds that developed last week.

The other plant has an unusual bumpy texture on the bottom side of one leaf, like the leaf is collapsing internally.

Both plants have nice green roots, although the aerial roots look a little dried up and some have tiny black specks. I'm suspicious of spider mites or fungus gnats so I treated all plants with insecticidal soap last week.

Any suggestions? Thanks!