frame drops / screen freeze as zac [GAMEPLAY]

entered a ranked game as zac and had an issue with the screen freezing for 10-20 seconds at a time, with no clear indicator of what could have been causing bug. played last night on multiple different champions and game was fine. i have had issues in the past with overwolf causing frame drops and since uninstalled. i restarted game about halfway through but it failed to fix the issue. looking for a prospective solution