The light bulbs were spot on. My board trimming was wrong and I need to sail with a higher nose with my Kona longboard in order to plane better. With the better rake, the board "pops" a bit more on a plane. I can also stay longer on a plane by staying a bit further back on the board.
And if I lose the plane, having the nose a bit higher brings the bow wave closer to the planing area. A gust combined with a strong pump and a push of the board forward gets me over the bow wave to a plane. I'm still not good at pumping to a plane, but I can now do it!
Thanks again Roger!