If it's growing strongly but not flowering then quite possibly it's in too shady a location - they need a bright, well drained spot to do well. If you could tell us more about how and where you are growing it we could give more detail.

I have 3, all in bright sunny locations, one is flowering with 4 fronds, that didn't last year, and the other 2 that did flower are still thinking about it!! I think they can be a bit flighty. If they do really get going they can be a problem in some gardens.....seeding in crevices and needing to be teased out.