The project manager should have conducted a thorough assessment of the team members' competencies and skills in relation to the training content before enrolling them. This would involve analyzing the training material to ensure it aligns with the team members' current skills and the tasks they are expected to perform. By doing so, the project manager could have ensured the training was appropriate and beneficial for the team members, thereby preventing the situation where the training felt too difficult and misaligned with their tasks2.
References:
PMBOK Guide - Seventh Edition, particularly chapters related to training and competency development1.
Project Management Institute's resources on project team development and training needs assessment2.

In the context of agile project management, when a team member is unavailable and it significantly impacts the deliverable, the project manager should perform an impact analysis to understand the extent of the impact on the project. The next step is to readjust the project schedule accordingly. This may involve re-estimating the remaining work, adjusting the scope, or re-prioritizing the backlog items. Once these adjustments are made, it is crucial to communicate the changes to the customer to set realistic expectations and maintain transparency. This approach aligns with the agile principle of responding to change over following a plan and ensures that the project continues to move forward in a controlled and informed manner. References: The answer and explanation are based on the principles found within the PMBOK Guide and the Agile Practice Guide, which are part of the reference materials for the PMP certification12. Additionally, the Professional in Business Analysis (PMI-PBA) reference materials support the importance of stakeholder engagement and communication, which are critical when there are significant changes in a project3.

According to the PMBOK Guide, 6th edition, section 13.3.2.4, the project manager should use interpersonal and team skills to manage conflicts and foster collaboration among stakeholders. Hosting a meeting is an example of such a skill, as it allows the project manager to facilitate communication, negotiation, and problem-solving between the parties involved. The project manager should also use the requirements traceability matrix, the project management plan, and the project documents to clarify the expectations and responsibilities of the vendor and the infrastructure manager. The PMI-PBA Guide, section 6.2.3.1, also supports this approach, as it states that the business analyst should use collaboration techniques to resolve issues and conflicts related to requirements. References:
PMBOK Guide, 6th edition, section 13.3.2.4
PMI-PBA Guide, section 6.2.3.1

The project manager should first validate the reason for the nonpayment of overtime pay. If the complaint is valid, the project manager should add it as an issue in the issue log. The issue log is a project document where all the issues are recorded and tracked. It is used to document and monitor the status of all issues until they are resolved. References: PMBOKGuide, 6th Edition, Section 4.3: Direct and Manage Project Work, and Section 11.6: Control Risks.