The value of DFF did not update when the probation unit changed

Summary:

We are trying to create a DFF to store the date value, and we have created a field modification rule. However, the DFF didn't change its value when the probation unit changed.

Sometimes, when I use 'Page Composer Tools', the system updates the value of DFF. I don't know why this happens.

Thanks in advance.

Field Modification Rule: (The below rule is for testing purpose)

Change Assignment Page: (We have updated the probation unit, but the DFF (Attribute Date 5) didn't updated its value)

Version (include the version you are using, if applicable):

24C