I got the impression that a section without roots had fallen off, but if that's not what happened, that's a good question. I used to have a bookmark on an article @ Clemson about Schlumbergeras but the article I could find there now is so similar to the one posted above from FL. Not the actual facts people don't need but vague and conflicting phrases about "let it get very dry" and in the next paragraph, "don't let it get too dry." I can't use that to do anything for my plant. It discussed that getting too dry could cause limbs to fall off, and that buds form between 50-85 when there are more hours of dark than light.
Easter cactus (Hatiora gaertneri - or whatever they're calling it this week) can bloom at any time of year.
These plants never knew a thirsty moment. But they are very tasty to squirrels. That's the main hazard for me when taking these outside. I keep them on the porch now, where squirrels rarely investigate.
And I haven't yet gotten around to potting 2 jars of cuttings of S. truncata that have been in water since last summer. Both of those jars had blooms over winter. I don't know that I will pot them at this point. The jar of water is so much easier and takes up so much less space. There are more pics of this somewhere, probably in "what are you propagating?" discussion on propagation forum. My drive is getting too full too fast to keep every pic I take to chat about.