[GAMEPLAY] Swapped summoner spells goes on cooldown while in combat

(This is a re-posting of another of my posts where I did not include the gameplay tag in the title and slightly clarified text, sorry about that) Sometimes when swapping spells with unsealed spellbook, the spell will go on cooldown while in combat, I have been unsuccesfull with replicating the bug in the practice tool, but it happened many times in the last 5 games in which I used the rune. While not completely certain, I believe that the bug might be caused by the in combat 10 second cooldown of the Unsealed Spellbook rune, that for one reason or another also affects the swapped spell if you have a new swap ready.

I have only seen the bug on Sejuani and Shyvana , although they are also the only champions whom I have used Unsealed Spellbook on. So it may or may not be a bug unuique to them.

Edit: This thread says that its Hexflash's in combat CD thats messing things up and not Unsealed Spellbook. Which is most likely true seing as i was using Hexflash as well and usually had that swapped instead of my smite. Thus that thread is talking about the "actual" problem.