Student-Question-Based Inquiry (SQBI) represents a form of inquiry where pupils design their research questions, hypotheses, and protocols. The "Savanturiers" program aims at helping teachers overcome their potential apprehension of SQBI by matching hundreds of elementary and middle school teachers with mentors. These mentors are usually researchers or Ph.D. candidates. This contribution aims at describing various tensions that arose during the mentorship of SQBI in this program through the lens of Engeström's activity theory. Field observations and semi-structured interviews with a sample of teachers suggested that numerous obstacles hindered mentor-practitioner collaborations. We identified at least three mechanisms that contributed to the paucity of interactions that we interpreted as contradictions of the activity system: mentors sometimes suggested activities that fell outside of the boundaries of curricula or were too time-consuming for a given group of learners. Alternatively, pupils' agency, notably in the phrasing of research questions, could lead them to explore topics or approaches for which the mentor had little expertise.