Certified GKH Gardening Expert
The issue is probably more about how much sunlight the plant is getting. It can be very difficult in the winter to get a hibiscus enough sunlight to both grow and flower, particularly if you have brought it indoors. Winter sunlight is just not as strong as summer sunlight. I would recommend trying a plant light on it. That may help, but you still may have to wait for spring for the best blooms to return.