Is it bugs or a fungus?

[Demeter]

(sorry for posting this in the wrong forum-- I don't know how to delete it now that I've posted this in the pests and problems forum)

I'm a beginner. I have these two orchid and one (the phalaenopsis) has wilted leaves, the other has something more serious. They are both indoor only. Can anyone please offer advice about what may be wrong and how to fix it?

I've taken them to a couple of nurseries to ask what's wrong, but they don't seem to know much about orchids. They just tell me I'm overwatering, but changing the amount of water given and frequency had no effect after 2 weeks.

Here are the photos:
Mtssa. Shelob
Mtssa. Shelob 2
Mtssa. Shelob 3
phalaenopsis