whether the cause of this is happening, is it something to do with the decision of the south korea government?
The banning decision of South Korean government could contribute on this part, but it doesn't mean the bitcoin is really affected on it. Countries support towards crypto is very in big help as it boost trust and confidence of investor to invest more. But we can't push them since they have also a protocol that could limit their power as bitcoin is being decentralized which is in contrary to it's system.