Hibiscus buds cut off
The buds look like they have been cut off about one inch below the bud. It is a clean cut and the buds look healthy.
This is very common for a number of reasons. If the weather has changed quickly, or the plant has been moved, then this can occur. This is also an issue if the plant does not receive adequate light. Underwatering or overwatering may cause this as well as not enough phosphorus and potassium in the soil.