Liquid Lightning not scaling w/ ranks?

Seroster

I noticed that, according to the tooltip, rank 1-4 of the morph Liquid Lightning (morph of lightning splash) are identical as far as damage & such goes. This would probably not bother me, except that the alternate morph (Lightning Flood) increases its damage when the ranks increases. Other place's tooltips, like Esohead, show the same thing.

I could not find anyone else reporting this, curious if this is a bug or as intended or some such? May make a bug report.