bugged interaction with xin and panth

during my most recent game i noticed that while i was useing my q if pantheon stunned me with his w it would reset it as if i had just casted it no matter how many stacks i had toward the knockup.

for example: i would hit twice useing my Q while his passive was down. he would stun me. the duration on my Q would refresh as would my stacks towards the knockup. as a result i would have to hit 3 more times to get the knockup