Turret Laser slow ignores CC Immunity

Laser Turrets apply a slowing debuff to their targets; this slow is bugged in that it currently ignores the CC Immunity on Master Yi, Morgana, and Olaf. The proof is attached (watch the speed stat in the screenshots). The Morgana screenshots are from PBE because I don't own her; Master Yi and Olaf are from NA.

I'm pretty sure this is a bug and not intended because no other slow ignores CC Immunity.