This is because the training of insurance companies has confidentiality requirements. Generally, it involves confidential information such as market planning, and requires geographical independence. Students cannot contact the outside world in any way.

Article 59 of the Provisions on the Administration of Insurance Agencies:

The training time of insurance agency business personnel shall not be less than 80 hours before taking up their posts, and the cumulative training and education time of each person after taking up their posts shall not be less than 36 hours, of which the legal knowledge training and professional ethics education shall not be less than 12 hours.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.