Natural shedding or problem?

[RedKim713]

I am new to slipper type orchids. I know that it is natural for orchids to lose their lower leaves, however, being new to paphs and phrags, I'm not sure if I am looking at a natural shedding of leaves, or if there is a potential problem. My paph is yellowing and then browning on the oldest leaf, but doing so from the crown. My phrag is sorting of yellowing and browning from only one side of a leaf, but it is the oldest. It also has a new growth starting at the base, on the same side the yellow leaf is forming. Can anyone identify if there is a potential problem with either plant or is this ok? I recently repotted both. The phrag was severly root bound. The paph is the one with mottled leaves.