Changes in specific DataMigrationMapping dont migrate in to Database

We are using the Data Migration Tool to synchronize data between the old and the new ERP system, and we use Git as a version control tool to contribute to our branch and review our work. However, we’ve encountered a problem: when we pull a data migration mapping with modified values in the corresponding JSON file, these changes do not affect the database. I’ve tried clearing the cache and changing the modified value, but without success. Interestingly, this process of pulling modified JSON files and updating the database accordingly works fine with other doctypes, such as ‘contact’. It’s as if Bench is ignoring my changes. Can someone help with this problem?

“I resolved the problem by updating the file /frappe/model/ to the new version from 15. Also, I needed to add ("data_migration", "data_migration_mapping") into the IMPORTABLE_DOCYPES list. That solved my problem.”