Completely concur with BorningGuy.
Poly relationships go through many stages. The growth stages often aren't nearly as fun as the NRE stages. But growth is necessary in order for the relationship to stay strong and be long-term. You will have times when the simple pleasures fall back into place. Don't be discouraged if there's some road blocks in between those times.
Given the overall very positive nature of the relationship between the three of you, I see it through optimistic lenses. I think you will get the present issues worked out (though I admit my forecasts are not all 100% reliable).
Love means never having to say, "Put down that meat cleaver!"