Explanation
According to the PMBOK Guide, the project manager is responsible for managing communications among project stakeholders, ensuring that information needs are met, and addressing issues that may arise during project execution. One of the tools and techniques for managing communications is feedback, which involves providing constructive and timely responses to queries and concerns from stakeholders. Feedback can help improve the quality and clarity of communications, as well as identify and resolve misunderstandings or conflicts. In this scenario, the project manager should discuss the issue with the engineer and determine how to prevent another problem by providing feedback on the service information document and clarifying any doubts or ambiguities that the service vendor may have. This can help avoid further delays and rework, and improve the relationship with the service vendor. Documenting the task on the kanban board, escalating the issue to the engineer's functional manager, or assigning another engineer to the task are not the best options, as they do not address the rootcause of the communication problem or help improve the quality of the deliverable. References: PMBOK Guide, 7th edition, pages 211-212, 10.3 Monitor Communications.