This study uses positioning theory to explore the reasons for Chinese learning assistants' misalignment with school pedagogical ideology and their resistance to professional learning at an international English-Chinese dual-language school. This study reveals that inconsistencies between three types of positioning practices (other-positioning, self-positioning, and second-order positioning) created tension in the ongoing identity work of Chinese learning assistants -- ultimately hampering their professional learning, which is essential for these learning assistants to adapt to a school's new operational model. Findings also bring to light influential factors within the institutional structure that contribute to the conflict between the three types of positioning practices. This study suggests international schools should move beyond fixing issues at the individual level (such as cultural differences), especially when challenges occur in teachers' professional learning, and should re-examine whether the institutional structure aligns or misaligns teachers' duties and rights with their institutional position.