I just spoke with Kaj, and he said that on client, the visuals for the guard shield are calculated per-client, and the actual collisions are only on the host side. I propose to make the visuals also calculated host side so that the visuals line up with the shield, leading to less confusion when it looks like things are just passing straight through the shield. The visual also takes some time to dissipate after you leave the pose, which creates a similar problem. I also propose to make it disappear instantly along with the hitbox, once again reducing this confusion.