What to do depends on finding out what is happening. I wouldn't expect a fungus to turn only the tips brown. Don't apply anymore garden chemicals without more information (is Funginex labeled for indoor use?). Try clipping some affected parts, putting them in a clear plastic bag with a good seal and taking them to a local information source such as a greenhouse company or garden center with a large house plant section, seeing if someone there can shed some light.

Down here we have USDA Cooperative Extension Service offices where such problems can be asked about, if you have anything like this there it would be a good place to try.

hi marric...i'm not a pro...but i would guess it is getting ready to sleep for the winter...kepp it in the basement with a little water til spring..gl