Special care for bring indoors, seem like buds are not opening all the way and some falling off before budding, alit of buds on plants though. Could it be adjusting to the change?
Moving Hibiscus (Potted) to Indoor Care
Plants go through shock when brought indoors unless the change occurs gradually. It may need more water due to dry indoor air. Supplemental light may also be needed to keep the plant flowering. Read more about indoor care: https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/hibiscus-container-care.htm