Farmer villagers' farming behavior is broken

Same here, two difeerent survival worlds last snapshot.

noticed this too, but it is very weird. They do farm when they're in a closed room (like a breeder) but not in the village farms

Can confirm this issue here on my server. However, contrary to Dawid, our breeder has this problem, and is 100% enclosed (besides the pathfinding to the beds, of course). I have noticed you can kickstart them farming again by breaking a crop for them to pick up the drops, and then they will start working the farm again. Wonder if it has something to do with loading/unloading the farm when entering or leaving the chunks?

I'm also experiencing farmer villagers seem to work way slower in 20w17a than they use to. This is in a brand new world made in 20w17a.

This is still present in 20w18a
The farmer outright refuses to harvest crops, plant crops or use bonemeal on the crops. However the farmer will use the composter and collect items.

After breaking and placing the composter serveral times, the farmer will sometimes begin to farm.

Those villagers were from spawn eggs. They were spawned in 20w** and since 20w17a, they're not doing anything

This appears to still be an issue in 20w22a.  Farmers stop farming.

@MukiTanuki could you please check the farmers data and perhaps post a screenshot of it? Look at the farmer and type the following command:
"/data get entity <VillagerID>" where VillagerID is the long string of numbers suggested for autocompletion.
There have been some people reporting the villagers will stop farming if their inventories are empty or completely full so it would be good to inspect the villagers data.

The villager's inventory pictured here is indeed full, but the peculiar thing about it though is that I can save a quit the game and the villager will start harvesting again for a while.  However over time the villager will completely stop harvesting.

If you think this is still an issue, please create a new ticket.