UPDATE: Found issue, there were no light sources above crops...
So, I play on a realm.
I have created a potato/beetroot and a wheat farm, underground. They are semi-automatic, so when a lever is flicked, water runs down the farmland and collects the crops (then I replant them).
However, crops seem to break by themselves. In the fields, there is a patch of farmland which breaks the crop magically by itself and drops the crop as usual. This happens in the same patches. There are no villagers nearby, and I was playing by myself.
Crop needs a light level 9 or higher to keep the seeds from popping out. Do you have any light source over the patch?