Just dropping this here, maybe it'll be fixed, probably not, as it's not a major issue, but at least the info is out there for someone.

The Cobblemon item "Medicinal Leek" is both eatable, and plantable, but unlike most crops, it is planted on water or waterlogged blocks.

AlwaysEat prevents planting of the leeks, defaulting the "Use" action to eat the item.
Removed AlwaysEat and the issue disappeared.
Blacklist and "Eatable" list did nothing to correct issue.

Forge 47.2.0
AlwaysEat 5.2

I might look into this during the christmas break but I sadly have very limited time right now (Just commenting to let you know that I did see it!)