there is a bug with the mercantile core where if you grab the item the turtle traded the villager's trade dissapears
version 1.20.1-1.2.4 and possibly others too (i haven't checked)
this is most likely caused by the turtle putting the itemstack reference into it's inventory rather than copying the itemstack and putting the copy into it's inventory,
so basically you need to make the turtle copy the item into it's inventory rather than the exact thing in the villager
SirEdvin
commented
1 year ago
there is a bug with the mercantile core where if you grab the item the turtle traded the villager's trade dissapears
version 1.20.1-1.2.4 and possibly others too (i haven't checked)
this is most likely caused by the turtle putting the itemstack reference into it's inventory rather than copying the itemstack and putting the copy into it's inventory,
so basically you need to make the turtle copy the item into it's inventory rather than the exact thing in the villager
Reported by dapimasta via Curseforge