This maybe because the government of Korea is against to this currency as it is a privacy coin that are commonly use by terrorist. XMR still at rank 14 base on coinmarketcap so I am wondering how they get a very low volume in Houbi exchange.

I hope it will not happen to other top exchange because it can surely affect the price of XMR if in case more exchanges will do the same. But upon checking the quick exchange like changelly, XMR still active so there is a big chance that this happening is more to XMR issue which is a privacy coin.