ch 21 seems weirdly fast paced has it been axed?

Sort of. Monthly Comic Ryu (the magazine in which the manga was serialized) stopped publication on paper with the latest issue and now just exist as an online webmanga publication. Butterfly Storage wasn't included in the migration so the series ended with Chapter 23.

Altough, the ending was labeled as "End: Part 1" so it seems the series isn't finished just yet. I would expect the author to resume the story at some point in Comic Ryu's website or maybe in another magazine.