Due to the sudden closure of the university following a major earthquake, a mathematics education course was rapidly transformed into a fully online, technology-enhanced learning environment, offering a unique opportunity to examine how pre-service middle school mathematics teachers engage with mathematical modeling tasks within a flipped learning framework. Adopting a phenomenological approach, the research involves 51 pre-service middle school mathematics teachers enrolled in a mathematical modeling course in mathematics education. Data were collected through assignments, videos, reports from the Academic Learning Management System, GeoGebra records, and semi-structured interviews. The data obtained from the Academic Learning Management System and GeoGebra were analyzed via descriptive analysis, whereas the semi-structured interviews were examined via content analysis. Pre-service middle school mathematics teachers experienced difficulties in modeling competencies, particularly in applying subject matter knowledge effectively and integrating technology into the modeling process. Technology-enhanced learning environments emerged as a critical support mechanism for fostering the use of content knowledge and promoting mathematical modeling as a problem-solving approach. Structured guidance and the integration of interactive digital tools within flipped learning environments proved to be effective in addressing the challenges encountered during the modeling tasks.