Lissandra ult didn't cast and went on full cd. Only banshees veil was my own

After looking at the replay it seems my banshees blocked a spell right as I cast my ult which might have caused the bug. I have the replay on overwatch so you can see my mouse and keyboard inputs. The crazy thing is that I don't believe I even clicked on myself when I ulted but still my ult didn't work. Looking at the replay seems to confirm I ulted an enemy champion. Again, no banshees or spellshields or edge of night or anything on the opponent team.

RIP D3 promos