Sivir spell shield is not blocking the damage from various AD abilities

I'm not sure if this is intended or not. Physical spells, particularly ones with a CC component seem to be dealing damage to Sivir through her spell shield. For instance, her shield is blocking the CC portion of Renektons stun whilst allowing the full several hundred damage through.

It's acting more like Morganas Black Shield and less like Banshees Veil in this regard.

Physical spells that have no CC portion, such as Varus' Q, and magical spells regardless of CC such as Ashe R are (as far as I have seen) being blocked normally with no issues. I don't believe I've encountered the problem as of yet with any ability that is not a damaging, physical spell which applies CC.

Granted, I only noticed and started paying attention to this about 2 games ago as I was beginning to get extremely frustrated with how weak Sivir felt compared to normal. So it's entirely possible it affects either more or fewer spells than I've indicated here.