Bard E Portal vision Bug

Hello, I just bought the new bard skin and took my first game with it, I got a mirror match vs another bard and sometimes I could see his portals and him traveling through, when i shouldent have... it happend like 3-4 times at minimum. I had no vision of that area and i saw him on minimap so i clicked there and i saw that he was traveling through portal. At the starting location of the portal was my "ice" chime, just to mention it if it could do sth with it.