Garen Q attack not hitting enemy nexus

For some odd reason as Garen i'm attacking enemy nexus hit my Q and he stood there and wanted to walk to something when im right clicking their nexus and it did not proc his Q action to hit at all.. I was not stunned silenced or rooted at all.. Twice this action has happened however the final hit on 3rd attempt with his Q connected after i had to reposition myself to more of the central part of the nexus in between the 2 downed nexus turrets.. Im not sure if it is a glitch with his hit box on nexus which shouldnt be an issue since his Q is an enhanced auto attack.. Please look into this when u guys have the time..