Xiaomi has sent out MIUI 12 beta builds to a number of its premium phones over the past few weeks, but is now suspending the MIUI 12 rollout for the Mi 10, Mi 10 Pro, and Redmi K30 Pro. The company seeks to better optimize the software, and has confirmed that the rollout will continue soon.
https://www.notebookcheck.net/Xiaomi-suspends-the-MIUI-12-rollout-for-the-Mi-10-Mi-10-Pro-and-Redmi-K30-Pro.470232.0.html