How to do that some lessons with a 2-week cycle always take place at the same time (for example one week Physics laboratory, second week – Chemistry laboratory)

You can create a new subject, for example, PhLab_ChLab, assign to it two teachers, two classrooms and two groups. Do not set cycle. Then, during first week, the first group can have Physics lab, second – Chemistry lab, and during second week – vice versa, and these lessons will always be at the same time.