So the Wrapped Ash Longbow's recipe is this:
Wrapped Maple Longbow
Aldgoat Leather
Antelope Sinew

This makes no sense, as you can't magically turn Maple into Ash by adding leather and sinew.

But much to my surprise and chagrin, this recipe is how it works.

So in order to synth this, you have to make a Maple Longbow (out of MAPLE BRANCHES and LUMBER mind you), convert that into a Wrapped Maple Longbow, then use that Wrapped Maple Longbow as the ingredient for the Wrapped Ash Longbow recipe.

I'm assuming the original recipe is supposed to be
Ash Longbow
Aldgoat Leather
Antelope Sinew

But they messed something up. I initially thought it was a small typo on the website and tried to use the above recipe but it wouldn't work. However using a Wrapped Maple Longbow did, so I'm assuming whoever wrote the 1.19 recipe list just typed it in without double checking that it made sense.

Could someone from SE please let us know if this is working as intended or if this was just an incorrectly implemented recipe?