This mixed-method study explores how students and teachers at a public high school in Ho Chi Minh City have responded to the revised National English Exam 2025. The data were collected from 91 students and 9 teachers to examine both the difficulties they encountered and the strategies they adopted to cope with the new exam format. The findings reveal that students struggled primarily with limited vocabulary, test-related anxiety, and unfamiliar question types, while teachers faced difficulties related to instructional time, material availability, and uneven student readiness. Despite these difficulties, both groups demonstrated adaptability while teachers revised instruction, assessments, and materials. By incorporating both perspectives, the study sheds light on how school-based actors are expected to interpret and respond to top-down exam reforms, a dimension that has received limited empirical attention in Vietnam. The in-depth findings offer empirical support for washback theory, assessment-driven learning, and self-regulated learning, and point to the need for greater institutional support to facilitate effective adaptation in high-stakes testing environments.