I have been doing a LOT of digging on this and no closer.
I tried replicating my results by making a second spell. For some reason I cant make that one into a scroll as it is failing somewhere I must have changed the first time.
However I have found back to my first problem some more info that narrows down where I am having problems.
My spell scroll is missing the "grey text" which I would suggest is part of the "Spell" not being correct.
Grey spell text
Does anyone know how this grey text is generated / linked to?