When retrieving an Account field such as FON_NAPA_FP__c through a relationship path like OrderApi__Contact__r.ACCOUNT.FON_NAPA_FP__c does not return the expected results, use an Apsona Multi-Step Report to explicitly link the related objects and retrieve the field directly from the Account object.
Alternatively, consider starting the report from Contact, since Account is directly related to Contact. This can simplify the report configuration and help retrieve the required Account field. In the reported case, the customer confirmed that the recommended approach resolved the issue.