Ryze cursor issue

When playing Ryze sometimes my cursor gets stuck on the target spell indicator cursor (blue target). This has occurred several times when I'm rapidly casting spells during arcane mastery. When this occurs I can't ping, move my screen using the minimap, or left click on anything. I can still cast spells, move, and auto attack normally. Sometimes it corrects itself through continued spellcasting, other times it persists until my champion dies. I tried taking a screenshot of it, but the cursor doesn't appear on screenshots