Knowledge and wisdom has three degrees; opinion, science, illumination. The means or instrument of the first is sense; of the second, dialectic; of the third, intuition.
Basic education Act 3 of 2020, section 114, subsection 8 speaks of prohibition of teachers from contacting business during school hours.
My point is that if a teacher is having classes after his/her normal working hours and on weekends, there is no legal restrictions in doing so