Today I notice something really weird and that's about what spell school a custom made spell has upon creating a spell in-game.

Earlier in my game I created a custom spell in-game and it had Restoration as a spell school, but today when I look at it again I notice it had a different spell school than it had when I created it.

Here is two pictures showing you exactly the same spell, but the http://www.theassimilationlab.com/forums/gallery/image/6843-morrowind-2015-09-17-212827319/ picture show you a different a spell school than the http://www.theassimilationlab.com/forums/gallery/image/6844-morrowind-2015-08-13-130535482/ picture had.

Why does the game engine change the spell school for a custom made spell in-game?

Multiple school spells are classified according to which component is hardest to cast. So, if you increase one of the schools to make it easier to cast, the spell will switch schools.