Hey,
Many issues have been reported by the community about 2.4.x, and I am unable to fix the for the time being (since I am on a trip), so I am recommending that server owners revert to 2.3.1.

Warning: The issues only affect ores as protection stones, so don't downgrade if you are using different blocks.

You can simply replace the plugin jar. Regions that have already been merged will have the secondary protection blocks ignored, so it is recommended to unmerge regions before downgrading.

Sorry for the inconvenience.