If it were me I would do some detective work and ask myself what conditions have changed over the years? Like have the trees around them grown and created more shade? (they like full sun or PARTIAL shade) or did they get buried deeper than usual with mulch (they like shallow planting)

I hope that leads you to an answer, good luck!

Yes, two things...I agree with Sue that they prefer sunny and in shade your flowering will be less. Also that in the wild, I'd say about 1/2 the leads may flower. Some just grow vegetatively and throw out new crowns vigorously.

I believe I need to move to a sunnier spot!!

Funny....I don't find them too demanding of sun. And they tend more to shadier locations in their native range as well. This is essentially a woodland plant.

Like their bigger cousins, they do benefit from division from time to time and too rich a soil will discourage flowering as well.