Star Guardian Lux's Ultimate doesnt do any damage like 5% of the time.

This is not an issue with any other version of Lux. Just her Star Guardian ultimate. Like 1/20 times it will not do any damage whatsoever to any target. This has been a bug that occurred for me multiple times now and I'm getting pissed off because of it. This match i sniped a Jarvan with my ultimate. He was at like 100 health and was in the exact center of it. Even the enemy Jarvan themself agreed that I hit him in the dead center and he should've died. I have even see this occur in the LCS once or twice yet no fix has been issued yet. Please fix this as I would like to safely play my favorite skin for Lux.