I peeled back the sheath, and as I suspected, two tiny rotten buds in the bottom.
I too will give this plant another chance. The new growth is getting well established and looks lovely so maybe this time
If you aren't supplementing with calcium you might want to give it a try. I am finding that since I have been adding a liquid Cal/mag to my water, many non bloomers and Catts with black rot problems are blooming and growing better. I only started last spring, so it may have been what finally encouraged this one to even try and bloom and maybe now it is on it's way to blooming.