1. Set up a plugin to cancel all player interact events and/or entity change block events.
2. Hoe some dirt into soil. Ensure there's water nearby so it won't revert back to dirt on its own.
3. Creative mode -> hover above the soil (high enough to do fall damage), then switch to survival mode and fall onto the soil.

Expected:

Soil is not changed to dirt, and player takes fall damage.

Actual:

Soil is not changed to dirt, BUT player also doesn't take any fall damage.