Starting new thread since the other one has a lot of incorrect information. It’s not limited to Quiver’s offhands.
Specifically there is a bug if you imprint an item that itself has a sealed affix it will prevent the node from working.
I tried a whole bunch of item types (all with sealed affixes) and none of them worked over 1000s of champion kills. I changed my loot filter specifically to avoid hiding them since there isn’t a filter for sealed affixes.
Once I swapped to a helmet WITHOUT sealed affixes I started seeing them drop properly.