Hibiscus do have the bad habit of dropping buds when they are stressed. This happens when the weather is hot - above 85 degrees, when they dry out, or if you give them too much or too little fertilizer. Use a slow release plant food like Osmocote to avoid the quick release of fertilizer from other sources that can cause stress. If you live where summers are hot make sure your plant gets afternoon shade. The good news is that bud drop does not mean your hibiscus is going to die. It is just letting you know it is not happy enough to flower. A braided hibiscus tree sounds like a beautiful and unique specimen so perhaps you should transplant it to a container next spring so you can move it to a cool location during hot spells.  Keep growing, Marianne Binetti