Sated Vi E Doesn't Activate

I noticed this happening when I tried clearing a large wave with Vi. I tried multiple times to reproduce this bug, and it happened each and every time.

When a champion has the sated devourer , it causes their auto attacks to attack twice each second attack. Now, im not meaning for her E to proc twice, but it doesn't even activate once! If you activate your E, and if your next attack is the double from devourer, there will be no damage given to enemies behind your aa target. I tried doing it multiple times, and each time I tried, I was never able to successfully do my E damage when AA sated. Is this a bug, or was it designed to be this way?