According to the PMBOK Guide - 7th edition, project artifacts are designed to keep the project work aligned to project requirements and business goals1. However, they are not the outputs or deliverables themselves. The guide emphasizes that while artifacts are important for project management, they are not substitutes for the actual deliverables of the project1. Therefore, the project manager should advise the team that focusing only on artifacts will not lead to the successful completion of project deliverables. Instead, the team should balance the creation of artifacts with the progress of actual deliverables.
References:
PMBOK Guide - 7th edition1.
Business Analysis Artifacts and Treasures | Geniusee2.
Business Analyst Artifacts: Definition and Types | Apiko Blog3.

When faced with a potential delay due to a vendor's resource shortage, the project manager should engage the project team to explore alternative options to adhere to the schedule. This aligns with the principles of project management, which emphasize proactive problem-solving and collaboration to maintain project momentum. The PMBOKGuide highlights the importance of communication and stakeholder engagement in managing project risks, including those associated with vendor deliverables. By discussing alternative options, the project manager can facilitate a solution-oriented approach that may involve re-allocating resources, adjusting work priorities, or finding other ways to mitigate the delay without compromising the project's objectives or quality standards.
: PMBOKGuide and the Project Management Institute's (PMI) resources on project risk management and stakeholder engagement12.

The sprint retrospective is an integral part of the agile approach, providing an opportunity for the project team to inspect and adapt their processes. When the product owner has concerns about the sprint results, it is important to address these in a retrospective meeting. This allows the team to openly discuss what went well, what didn't, and how they can improve in the next sprint. It's a collaborative effort to enhance the quality and effectiveness of the team's output and to ensure alignment with the product owner's expectations12.
References:
Scrum.org resources on Sprint Review3.
PMBOK Guide - Seventh Edition4.
Professional in Business Analysis (PMI-PBA) Reference Materials5.

According to the PMBOK Guide, an agile project is an adaptive life cycle project that follows an iterative and incremental approach. In an agile project, the project manager facilitates collaboration and empowers the team to deliver value. When an unidentified risk becomes an issue, the project manager should help the team review the project approach and initiate the corrective actions to address the issue and prevent recurrence.
Asking the sponsor to approve an additional iteration or money is not agile, as it implies that the project scope or budget is fixed and cannot accommodate changes. Asking the team to include the contingency plan in the iteration backlog is not appropriate, as the contingency plan should have been developed before the risk occurred and should be executed as soon as possible. References: PMBOK Guide, 6th edition, pages 18-19,
456-457, 686-687.

The Project Management Institute's A Guide to the Project Management Body of Knowledge (PMBOK Guide) lists the four initial (pre-execution) processes of procurement as: Procurement Planning, Solicitation Planning, Solicitation, and Source Selection1. The inputs to Procurement Planning include the project scope statement and information on available resources and market conditions, and are used to drive a build-or-buy analysis, which results in a procurement management plan and a Statement of Work (SOW). The SOW is used as input to the Solicitation Planning process, during which a Request for Bid or RFP-like document is developed to elicit vendor proposals, in addition to the criteria to be used to evaluate vendor responses or software1. Therefore, even in the case of urgency, it is important for the project manager to follow the company's standard vendor selection criteria process to ensure the selection of a reputable vendor that can meet the project's needs. References:
https://www.pmi.org/learning/library/vendor-selection-process-predictor-project-success-8514