Summon Reaper of Eviscerating Aoe Attack

When using Summon Reaper of Eviscerating with high enough cast speed (seemingly around 100% increased cast speed) it skips the aoe attack that it does after a dash and just does another dash.

I'm guessing this isn't intended because it likely decreases the damage of the skill and significantly worsens its clear speed.

Here's a playlist with two videos, showing 70% increased cast speed vs 104% increased attack speed.

https://www.youtube.com/watch?v=NtLZL88CGY4&list=PLSihvLPEXTzk8rkJwvFdKpH3020OLjvLB

I think it might be something to do with the dash and aoe taking longer, because the aoe works fine while staying still, I also don't know if anything else breaks with higher attack speed as I don't have easy access to higher cast speed.