I am not an export by any means and do not have too much of experience, but it looks to me the soil is a little bit heavy and holds too much water.

I grow mine in nearly pure bark, and I advise others to try bark, as well.

Josh

Josh you are right, people who grow this genus of plants need to do research and find out where they live. Most live in trees, as you know tree braches do not hold water, they are tropical so get frequent water from the rain. I would use distilled water or water from a well, it needs very fast draining water, perhaps hanging the pot under tree braches to give it filterd sun. Mine are all in hanging pots, I also use orchid bark, treat the plant like a tree orchid and see if that helps. Follow whatever Josh said. Norma

Pls. do a search for the Holiday Cactus link which gives good care & info. I can't cut & paste on this computer, so I can't see your pix. It MAY have been unnecessary & a mistake to pot up larger; not commonly necessarily w/ this plant & its small roots.

Your mix could be too wet or dry, either of which can cause sections of the plant to drop off. I'd try rooting them if they're not limp already. Sometimes they just do this.

They really do need very fast draining mix, I use AV soil w/ a lot of perlite mixed in. They don't care to be kept moist contrary to what some folks suggest.