Project-based (PB) learning has become increasingly popular in computer science education, particularly as studies have found that the teaching style better prepares students for future careers and improves learning outcomes through increased student engagement. Online forum usage is one measurable component of engagement. In order to study the impact of PB learning on online forum engagement, Piazza usage data from seven online computer science courses at a higher education institution were collected and examined. We analyzed the differences in online forum usage between PB and assignment-based (AB) learning, in addition to differences between men and women in each course type. Specifically, this study builds upon and replicates a previous study on Piazza that measured student engagement, anonymity usage, and peer parity. We found that students in PB courses were less actively engaged in online forums than students in AB courses; they were less likely to ask and answer questions on Piazza but were more likely to view posts and be logged on more days. Across both course types, students posted anonymously a similar amount as a proportion of the total number of questions and answers and experienced a proportionally similar amount of peer parity. Our findings mirror prior results on gender engagement on Piazza. Across both PB and AB courses, women were more engaged, asked and viewed more questions, posted anonymously more frequently, and were less likely to experience peer parity than men.