The Xiaomi Mi MIX3 5G is the first 5G phone from Xiaomi and is only available in some parts of Europe. In terms of system updates, it will not be able to upgrade to the latest MIUI 12.
The Xiaomi MIX3 5G was released in May 2019, and it's been over a year since then, but the operating system is still MIUI 10, and the kernel is Android 9.0. Its last system update was v10.3.23.0.PEMEUXM, released in Europe in February this year.
Xiaomi customer service has previously revealed to users that the Xiaomi Mi Mix3 5G will be upgraded to MIUI 12 in October 2020, except that the kernel remains the same as Android 9.0. But now it looks like this superficial update won't be available either.
Recently, Xiaomi pushed MIUI 11 v11.0.5.0.QEEMIXM stable beta to Xiaomi Mi Mix3 4G version, the kernel is based on Android 10.0. but in the Q&A session, Xiaomi confirmed that the Mi Mix3 5G version currently has no plans to update, there may be an upgrade in the future, but the timing is unknown.
Xiaomi even asked users not to pursue the upgrade plans for the Xiaomi Mi Mix3 5G version, and if there are any, they will be announced on the official forums.
In other words, Xiaomi has pretty much given up on system updates for the Xiaomi Mi Mix3 5G version, and there will be some minor updates in the future at most, but the chances of MIUI 12 are basically zero.
