The activated Infused Crystal Shovel and Axe dupe the blocks they break when their AOE effect is active. While this isn't quite an issue for the Axe, it is for the Shovel as it allows you to dupe a wide variety of blocks.

I'm unable to replicate this with just AS. Need some additional information here, what version of AS (number please, not "latest"), pack involved, exactly how you are seeing this replicate on your side.

Welp, HF got it to replicate.