hello,
I’m doing 10k, and I found this behavior:
if this is just me drunwand this is just feature and not a bug please forgive me and tell me instead hhah!
あく is an alternative meaning, that’s why it’s accepting it. In truth, 空く can be both read as すく and あく. The nuance is in a way very similar, but it exists. To understand the nuance, read this post below 
Just to maybe clear up some confusion: the Core 10k is published by the user @hinekidori, so most things that you might find on it might be worth directing to the deck’s creator over to Kitsun itself. Each deck creator from the Community Decks has their own topic for this type of reporting.
Core 10k’s thread:
No worries! The forums are a place for you to get your questions answered 
So feel free to come here anytime you feel you’d like some clarification 
