How did you mount the blank on your lathe? If you used a stopper mandrel as they show in the instructions, the hole should be centered. However, if you used dead center in your headstock, it might not have kept your blank perfectly centered.
I had that happen recently with a 1/2" hole. Fortunately I noticed it before I turned it all the way down. I put a small piece of paper towel on one side of the hole & remounted the blank and was able to complete the turning with the hole centered.
You might also check your drilled hole to be sure that it's parallel to the sides of the blank. If the hole is at an angle, that will affect how the scoop attaches.