[Gameplay] Graves-E (Quickdraw) does not seem to proc Iceborn Gauntlet Spellblade

When building Iceborn Gauntlet on Graves, I noticed that my E-Spell (Quickdraw) did not proc the Spellblade Passive of Iceborn Gauntlet if I used it after using a basic attack. I noticed this while farming; after dashing into the wave of minions, my Spellblade was applied; however, when I, after a few seconds, dashed again, my next basic attack did not apply the Spellblade effect. Recreate as follows:

1. Basic-attack
2. Cast E (Quickdraw)
3. Basic-attack. Spellblade will not apply. I have noticed this in three separate and consecutive games of playing Graves; therefore I am relatively certain that this is a persistent issue.