On my server, I created a villager breeder/farm and everything worked perfectly fine in the beginning. I have 1 brown robed villager and a blacksmith trapped inside. There are 36 doors surrounding the building. The first time I built this, I used carrots. The villager harvested and traded for a while and produced 1 offspring. Once they were bred, the villager completely quit harvesting.

I tried several things over the course of several hours to get it working again (harvesting/replanting/bonemealing crops, trading with each villager to get them to breed, killing the offspring) but nothing worked so I completely tore the structure down and rebuilt it.

The 2nd time, I built it exactly the same as the first time, but tried planting seeds instead. Again, everything worked magnificently until the pair bred. Now the villager will not replant, nor harvest crops. I have searched several websites to see if this is an intended feature and cannot find anything to support that so I believe this could be a bug.

Additional Info: I also could reproduce this in my single player world, but I noticed that it's not JUST after they breed. I tried this with all crop types so I know that it's not just the inventory filling up with wheat and no seeds.