I think you need to take a new cutting, the one described above is not in good shape. Water rooting is okay, I think it might be simpler, though, when the roots look well established, to just start adding every day or so a little potting soil to the rooting container. You then would not have to give roots the shock of going directly from water into soil mix.

Something doesn't sound quite right. It sounds like the roots/stem rotted in the potting mix or dried out too much to take up water.

Try perlite instead of soil mix next time to root your canes if you use lots of water. Potting mix should be okay but do not keep it sopping wet.