Plumeria cuttings and stem rot help please?

fungus or bacteria cause rot. Try sterilizing your rooting soil before planting by putting in oven at 200 degrees for a couple minutes. Let it cool before planting. Use distilled water for the first couple waterings to be sure there is no chlorine to inhibit new roots. You might give the stem a quick wipe with rubbing alcohol then rinse with distilled water to make sure it is clean of disease. I would not put it in FULL sun untill it shows growth. Partial sun would be plenty.