I got this plant cutting a little bit ago and has been doing very well. A lot of roots have grown and a bunch of little shoots have popped up! It’s been doing great but I just checked it today and the stem seems to be falling apart? It’s very flimsy and the outer part of the stem is falling off. It’s also a bit mushy. When I tried to put it back in the tube, the only leaf fell off. What happened? What did I do wrong? What do I do now?