The Mi Mix 2S and Mi Mix 3 have received new MIUI 12 updates. Xiaomi has now started bringing the global versions of the handsets onto its latest OS, following equivalent rollouts on other branches of MIUI.
https://www.notebookcheck.net/Xiaomi-Mi-Mix-2S-and-Mi-Mix-3-receive-new-stable-MIUI-12-updates.490032.0.html