[GAMEPLAY] Fiora Riposte sometimes triggers, but fails to block incoming CC

Occasionally, Fiora's W will trigger (meaning the spell fully casts), but it will not block CC applied right as it begins. This may be intended, but the specificity of the timing makes me think that this is not the case. To be very specific, the bug occurs only against cc (and potentially damage, but I've only noticed it with stuns) that is applied RIGHT as Riposte begins.

Reproduction (Doesn't always work, but I think that has to do with the near-perfect timing needed to create the bug):

1. Fire some form of hard CC at Fiora
2. As Fiora, wait to Riposte until the last possible moment
3. One of three things will happen: 3a. Fiora will properly Riposte the CC, with the spell turning golden and the Riposte stun being procced (normal behavior). 3b. Fiora will be stunned, and either not Riposte at all, or Riposte will be buffered to cast AFTER the stun duration is complete (normal behavior). 3c. Fiora will be stunned, but while the stun is active use Riposte. Riposte will still block CC/damage applied at this point, but the original stun does not proc the Riposte counter-stun, and the indicator does not turn gold (the bug). It is most noticeable when the stun duration lasts longer than the Riposte played over it.

My friend and I reproduced this using Taric's E, but originally found this bug dealing with Brand stun, and we later reproduced the bug with Hecarim E.

The footage linked is of the bug as tested with Taric's E. The first clip is the intended behavior, the second clip is the bug, and the third clip is a confirmation that the bug does not have to do with which way Riposte is angled relative to the stun. https://youtu.be/ECrFnSXK1Vs