This just started happening for me too, though it is slightly different. The potato or carrot will still uproot after a few seconds, but will pop out instantly if there is another crop planted beside it.
Steps to Reproduce:
1. Till a soil block beside a water block
2. place a carrot in the tilled soil
3. plant a second carrot in a tilled soil block beside it
4. the carrot will instantly uproot.
5. alternatively, plant them more than a block apart, and they will stay in for a few minutes, then pop out.
*Edit: Just checked, and the same thing is happening with wheat and anything else placed in tilled soils. Attached a screenshot to better demonstrate?
To go with my comment.