We have enabled audit trail for one of our attribute in classic ppm but the old and new value column is not getting updated in modern UI. This is started happening after updating query behind the lookup of that attribute.
When attribute is added to the audit trail there is an audit function that is created with the SQL of the lookup at that time, without following steps below that audit function will not get updated and cause audit not to work properly.
1. Remove attribute from the audit ad Save.
2. Run XOG to update the query of the lookup.
3. Add attribute back to the audit and Save.