Ruby Sightstone Passive

I just finished a match using Morgana Haunt Pale (got S+ victory, yay :D). At 23:03 I bought Zhonya's Hourglass and at 24:48 I bought Ruby Sightstone (I had blue Sightstone for awhile but didn't upgrade it), between 27:30 and 27:40 I used Hourglass's active while stalling a Vi. Directly after I came out of stasis I used my Tormented Soil then directly died afterwards and it proct'd my Frost Queen's Claim 3 times. Once I was dead I noticed my hourglass still had the full 120 second cooldown (minus a few seconds mind you because of the delay between coming out of stasis and dying, I believe it was at 117 when I noticed it). So apparently my Ruby Sightstone didn't properly adjust the cooldown of Hourglass. UNIQUE: Item Active cooldowns are reduced by 20%.