Prolonged school closures, forced isolation, and mutations in social interactions due to the COVID-19 pandemic have posed challenges for actors in the educational context; teachers, in particular, have had to develop new instructional strategies to ensure that lessons could continue. The present research measures in a group of 374 Italian teachers—curricular and specialist support teachers—the relationship between self-perceived instructional competence, self-efficacy, and burnout. The present research, conducted between April and December 2020, represents the second part of a larger study conducted from November 2018 to October 2019, which was replicated during COVID-19. Participants completed an anamnestic questionnaire, the Assessment Teaching Scale, and the Maslach Burnout Inventory in both phases of research; an ad hoc questionnaire (to measure teaching practices) and the Teacher Sense of Self Efficacy Scale were added in the second phase. Data confirm that general level of burnout increased and personal accomplishment was reduced during the pandemic; elevated personal accomplishment appears to be a predictor of emotional, socio-relational, and didactic competences before and during the pandemic. Feelings of frustration and accomplishment represent some manifestations of distress caused by the pandemic condition; these dynamics favor the crystallization of roles and behaviors towards the perception of metacognitive teaching processes.