Ahri charm bug [gameplay]

Ahri's charm has the capability of stopping certain unstoppable ultimates. So far I have seen it stop Malphite's unstoppable force and Kalista's fate's call (the knock-up portion where the support comes back out, the support got charmed and the knock-up did not occur). I have been able to test the Malphite ult, and it is consistently negated as long as Ahri's charm hits malphite before he reaches his knock-up location.