I know I'm far late. I encounter the same situation. Which when I want to print report from other model, the report is empty

Here is my solution without making additional method on the target class

class HrContract(models.Model):
    _inherit = 'hr.contract'

    def print_nominee_report(self):
        account_payment_id = 1

        model = self.env['account.payment'].browse(account_payment_id)
        return model.env.ref('account.action_report_xxxxx').report_action(model)