South Korea was one of the first markets in which commercial 5G had become available, although the networks in question use the sub-6GHz form of the connectivity. Now, however, LG's division Uplus and Qualcomm have implemented the first mmWave alternative, intended to serve an academic campus in this country.
https://www.notebookcheck.net/LG-Uplus-and-Qualcomm-bring-mmWave-5G-to-South-Korea.508714.0.html