That is intentional, otherwise beacons would not work in the nether.
Magma Cubes were never affected by fall damage, this is intentional.
Cows (and other animals) can only breed every 5 minutes.
If they've breed in the last 5 minutes, the will behave exactly as you've described it.
Check if you have any other villagers in a 48 (or better 96) block radius around those ones, which might have been assigned to the workplace.
Any unemployed villager should be able to assign themself to an unused workplace in a 48 block radius and will only forget about it's preofession, if the villager moves 96 blocks away from the workplace (and has not been traded with).
Due to the changes to the rendering engine in 1.14, VBO support is now required and therefore can not be disabled anymore.
https://twitter.com/SeargeDP/status/1060455384471793664