You may already realize this, but it could just be going thru shock and/or showing signs of stress from being moved around so much - nursery - HD - you.
Some that I've bought have been fine, but others go through a bit of a slump, then recover quite nicely.
Barb

Sounds like shock to me too. But since we are on the dropping bud topic, what if you have an established hibiscus that's been in the ground for years and now suddenly drops a bud periodically? This same plant is also having leaves turn yellow very fast and also drop. I am also in south Florida. I thought maybe not enough water but they made it through our winter drought with only infrequent waterings by me. Our rainfall is on the rise now. Would a few months of drought followed by sudden flooding downpours cause the leaves to yellow? Thanks!