I had a simple sweet berry farm on my server in 1.16: Sweet Berries on farmland on hoppers. Foxes in with the berries and they harvest them. When I updated my world to 1.17, they stopped harvesting the berries. I tested the design in a single-player creative world and found that if the berries are planted on normal dirt, the foxes harvest as expected, but only when they are on farmland, no harvesting.