Text ID field on the Fiscal Reference form allows edit after Invoice has been posted.
To resolve the issue the following change can be made which will not allow edit of the Text ID field.
1. Open the AOT
2. Expand Forms
3. Locate and expand TmpFiscalReference_BR
4. Expand Data Sources
5. Expand TmpFiscalReference_BR
6. Expand Fields
7. Locate LegalTextID
8. Right-click on LegalTextID and choose Properties
9. Locate the AllowEdit property and set the Value = No
10. Save the changes to the form.