This study investigates how remote learning due to the COVID pandemic impacts students' ability to keep up with the pace of instruction in a university level physics course, with a focus on the heterogeneous impact of remote learning on different demographic groups. Student learning data is collected from 70 online learning modules assigned as both online homework and self-study material in both Fall 2020 and Spring 2020 semesters, with the first 41 modules being assigned before campus closure in Spring 2020. Students' ability to stay on track is measured by three data indicators: percentage of modules submitted before the due date, percentage of modules submitted early for extra credit, and percentage of modules properly engaged with. The student population is divided into two demographic groups according to each of the four demographic variables: Gender, Ethnicity, Transfer Status and First generation status. All three data indicators from both semesters are first compared between each pair of demographic groups within the same semester, and then compared within the same group between the two semesters. Exam and course scores are also compared between demographics groups in Fall 2020 and against scores from the Fall 2019 semester. The analysis revealed that remote learning significantly reduced on-time and early submission for first-generation students, but increased the frequency of early submission for transfer students. Under-represented minority students had higher percentage of engaged modules during the pandemic, while non-URM students had the same level of module engagement before and after the pandemic. These results suggest that pandemic remote learning had very different impact for students with different demographic background, and future instructional design should strive to provide more flexible options to meet the various needs for a diverse higher-ed student population.