I have 2 clematis armandii indoors. I got them about 2 months ago, and repotted them in bigger pots. They are sitting on a very large window. They thrived until about 3 weeks ago, and doubled in size.

However now, all the leaves are getting brown. I never overwatered them, but maybe the fact that they sit in pots with a saucer is not good... I don't know.

Also, there is some kind of extra fine spiderweb looking stuff on branches, which is why I am thinking it could be fungus. There also seem to be weird stuff growing on the outer rim of the pot itself (?)Yellowish/whitish. Can anyone help me out?