cancelled invoice did not reverse the complete tax amount

Summary:

Content (please ensure you mask any confidential information):

A Project Invoice is cancelled and a project credit memo created with correct amount and tax.

but in AR, the credit memo is created with complete invoice amount, but not with complete tax.

difference is in tax amount.

AR is still showing this difference tax amount as remaining open balance.

Any insight on the cause and how to fix this.

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

24C 27th Sep CWB

Code Snippet (add any code snippets that support your topic, if applicable):

SR 3-38499612831