Homeguard causing champion to run incredibly slow

Last night in every game I played as Blackfrost Anivia, regardless of what runes I took, at random when I left the fountain instead of running fast with the homeguard speed, I get the homeguard animation and barely make it passed the nexus before homeguard wears off. It made me miss a few crucial teamfights and it was present in EVERY game so I can probably repeat it if I need to. (It shows up in the replays so I guess I can make a video of it.)

I didn't try with any other champion or use any other skin.

Since I play almost exclusively Anivia this is a major hit to me.

Edit: It didn't occur when I played with Festival Queen Anivia this afternoon.

Edit: Added youtube link. https://youtu.be/WLNlRSXHcL0