Is the housing management office responsible for the theft of the house?

To be responsible, the reason is not that you are not allowed to install anti-theft nets, but that you have not fulfilled the property management contract and legal obligations.

According to the property management regulations

Forty-seventh property management companies should assist in the safety work within the property management area. When a safety accident occurs, the property management enterprise shall, while taking emergency measures to assist the rescue work, report to the relevant administrative departments in a timely manner.

If the property management company does not take appropriate anti-theft measures, such as video surveillance, but no one is on duty, it should be responsible for your losses. As for the anti-theft net, it is not the property management's fault that many cities are not allowed to install it now.