How to force update of space-time attributes when performing update

[cchjgood]

Expected behavior

The original entity attribute has a value. Change a certain attribute to null through the front end and pass the entire entity to the back end. During the update, it is found that this attribute has not been modified to be null. Check the executed SQL and there is no update to the null value.
Tried multiple versions of 15.x

Actual behavior

Steps to reproduce

  // some java code

  // some logging output