Villagers don't pick up items

Villagers used to pick up bread, carrots or potatoes tossed to them by players. This could be used to encourage breeding. Tried all 3 items on butcher and shepherd villagers and no items were picked up by villagers.

I originally had mobGriefing set to false, but observed the same non-pick up behavior after setting it to true. I did not restart the server yet, so I don't know if that would make a difference.

Not sure if these details matter:

1. these are "cured" villagers from zombies. Haven't tried it with original, non-cured villagers.
2. gamemode is survival, but I only tried this with an OP'd login, but in survival mode.
3. non-pickup happens before and after first trades.

I searched for Villager-related bugs, but didn't see this one listed.