Many students think contacting their instructor shows that they weren’t paying attention or that they are the only student did not understand something, so they often keep quiet and go on trying to do work that they do not understand. Other students think that their teacher is their own private tutor, so they email or message the teacher several times a day to ask questions that likely have answers in the syllabus and in the learning module instructions.
It's a balancing act, if you don't know or understand something, it okay to ask your instructor for help, but overloading them with so many questions can make it hard for them to help other students. If you have trouble understanding the material, you may need a tutor.