The levels of adequacy of movement behaviors after returning to in-person school activities following the COVID-19 pandemic are not yet well understood. This study aimed to assess the adherence of Brazilian minors to the recommendations of the 24-Hour Movement Guidelines (moderate to vigorous physical activity, recreational screen time, and sleep duration), as well as overall adherence to these guidelines, after the relaxation of COVID-19 social isolation measures and the resumption of in-person schooling. A cross-sectional study was conducted with parents or guardians (39 ± 7.8) of minors aged up to 18 years of age (3.8 ± 2.5). A total of 172 individuals responded to the questionnaire. Data were compared with those obtained in the Survey of the Adequacy of Brazilian Children and Adolescents to the 24-Hour Movement Guidelines before and during the COVID-19 Pandemic. There was an 18.6 percentage decrease (p-value < 0.001) in overall adherence to the 24-Hour Movement Guidelines when comparing the periods before the COVID-19 pandemic (March 2020) and after the return to in-person schooling (March 2021). The largest percentage drop in adherence between these periods was observed for moderate to vigorous physical activity (27.4%; p-value < 0.001) and the lowest for sleep (10.5%; p-value < 0.001). Adherence to the 24-Hour Movement Guidelines did not return to pre-pandemic levels with the resumption of in-person school activities.