A misconfiguration in the firewall is the most likely cause of the issue. A firewall is a security device or service that controls the incoming and outgoing network traffic based on predefined rules. A firewall can help protect the cloud-hosted web application and the managed database from unauthorized or malicious access. However, if the firewall rules are not configured properly, they can also block the legitimate communication between the web application and the database. For example, if the firewall rules deny the port or protocol that the web application uses to connect to the database, the web application will not be able to receive data from the database. To fix this issue, the cloud engineer should review and update the firewall rules to allow the necessary traffic between the web application and the database. Reference: CompTIA Cloud+ CV0-003 Certification Study Guide, Chapter 9, Objective 9.2: Given a scenario, troubleshoot common security issues.