It happens while tilling land, as well. If you walk over the tilled land right after tilling it you will take fall damage if there are no blocks underneath it.
I know it's fall damage because I took reduced damage when equipping feather falling IV boots.
I have the exact same problem on my Xbox (Bedrock Ed.).
It happens while tilling land, as well. If you walk over the tilled land right after tilling it you will take fall damage if there are no blocks underneath it.