The Weekly update 21.4.15 has been officially released for Mi 11 Pro/Ultra / 11 Ultra (codename is star). Before updating, please make sure you have downloaded the exact ROM matching your Xiaomi phone/tablet. In Fastboot mode, you can check model code by typing
fastboot getvar product in cmd/shell.
Download Mi 11 pro / ultra (star) China MIUI 12.5 21.4.15 Recovery ROM with Android 11.0. Firmware size is 4.4 GB.