Villagers don't break wheat to get seeds

I hav an automatic wheat farm where villagers are supposed toplant the seeds to grow wheat. Then they try to give the bread to an other villager and the bread gets sucked up by a hopper.

My Issue is that when the Villager runs out of seeds, he doesn't break the fully grown wheat to get new seeds. Also he doesn't make bread anymore. This exact farm worked in previous versions.

Edit: I checked the villagers inventory and he has lots  of space for seeds and wheat. In fact he picks up seeds if i drop it to him and starts planting them, but he won't harvest the wheat.