Three accounts on the individual differences in metacog monitoring: The competence-based, the performance-based, and the awareness account. This paper supports the first account.
"this study shows no evidence for a general bilingual advantage in SL, although bilinguals may outperform monolinguals under specific experimental conditions such as SL tasks that place high demands on working memory processes"
https://www.sciencedirect.com/science/article/abs/pii/S0010027723002937
https://www.sciencedirect.com/science/article/abs/pii/S0010027723002731?