I would think the problem is not enough sun. It could also be a nutrient imbalance. Too much nitrogen relative to phosphorus and potassium can cause lots of green growth without much flowering. Pruning should not be an issue since they bloom on new wood. I cut mine down to about a foot tall in the spring. You can wait to prune until you see new growth to determine how far the die-back was in winter. Leaving it up in winter protects the plant somewhat and provides winter interest too. For me the store-bought butterfly bushes always performed poorly. They usually only lasted a year or two and never got any size to them. Then I wintersowed some seed I got in a swap and have had the resulting plants for almost 5 years now. The one in full sun shoots up to almost 7' tall every summer after cutting back to 12" in spring. It is loaded with blooms that I deadhead to keep it blooming until a hard frost. I have never fertilized it, but we do have a more clay based soil that retains nutrients. I think some of the more cultivated varieties and hybrids have probably sacrificed hardiness and vigorousness for the sake of compact size and new colored blooms.

Just the way the DNA is programmed. I can't remember if I've ever gotten double blooms with my Thanksgiving Cactus, I want to say once But I'm not certain (and if it happened it was not much farther apart than Thanksgiving and Christmas, not your Fall and Spring scenario)

Hi Holly. Is the door in between the sofas the main door in and out of the room? Your biggest factor here is layout and paint. Sorry you just painted but its the wrong color to work with your existing pieces. Also dividing the paint color below the moulding strip is making the room feel squat because of the sharp color contrast. One color to the ceiling would be ideal.. Really white or a pale pale pink is your friend here and would have been preferable. The place to have brought in some color accents would be in a rug to ground the space and some pillows. The minty green isnt the right tone. I would pull the rose tone from your fireplace tile and a deeper green. accent with warm whites. A sheer warm white drapery panel won't make the window seem so heavy and you could even mount these to the outside of the window bump out. A round coffee table would be a better fit for the furniture layout. I would do chests on either side of your fireplace and I like where you were going with the round mirror but I would do one over each chest and then bring in a piece of art for over the fireplace. Try moving your art you have on either side of the fireplace above your sofa and see how that feels. They may be too small but its worth a try. Is there a reason for the moulding behind the sofa? Your black floor lamp is overwhelming the room and I would do something that ties into the gold mirrors. If that door us used then that would not be my choice for a place to have a lamp. Thats hard to say without seeing where your travel paths are in the room. A side table and lamp to anchor the corner near the windows. Here are some ideas to tie into what I am saying.

Susan A plant that's only a year or two old, might be genetically programmed to grow mainstems first and then, push out some side branches. It's all genetics. Before you trim the top to induce back budding....take a Google-look at "tower Adenium", both pictures and You-tube videos. You just might want to rethink topping your Adenium. Another alternative......grow your tall Adenium to the height that suits your fancy and then, graft a new top onto the original tall stem, branches and all. Just cut the top off the original stem, and graft stem sections onto the original stem. Grafting by using super-glue, works. There are videos that explain how this super-glue grafting method is done. You literally, can create the Adenium that you want, growing the flowers that you want, by super-gluing. Explore the possibilities. BTW, you can even use super-glue to graft side branches onto your lanky Adenium, to fill it out. Good luck.