My guess would be your soil may not be acidic enough. Medinella grows wild & blooms like crazy where I live here in the rainforest, very acid soil. The bushes are coming into bud right now.

Thank you. I will try some acid fertilizer and see if it does the job.

I have a Medinella in Seattle and it grows well here too (indoors). I have found that it is important to cut all fertilizer and give only one treatment of bloom fertilizer before blooming season (spring). After spring/summer blooming I give it one feeding of fertilizer before fall sets in. I also water it only enough to keep it alive in fall and winter, otherwise the roots will rot from lack of appropriate heat.
Now how do I safely prune it? I am afraid it won't leaf out on old wood..