A deployment template is a file that defines the resources and configurations that are required to deploy a cloud solution1. A deployment template can be used to automate the deployment of cloud infrastructure for clients, ensuring consistency and efficiency2. However, if the deployment template was modified, either intentionally or accidentally, it could cause discrepancies from the baseline in the configuration of infrastructure that was deployed to a new client. For example, the template could have different parameters, values, or dependencies that affect the outcome of the deployment3. Therefore, the most likely cause of the issue is that the deployment template was modified.
Reference:
1: What is a template? - Azure Resource Manager | Microsoft Docs3
2: Automate cloud deployments with Azure Resource Manager templates - Learn | Microsoft Docs3
3: CompTIA Cloud+ CV0-003 Exam Objectives, Objective 2.2: Given a scenario, deploy and test a cloud solution