Hello,
1) Install Magisk via TWRP (+ Basic Configuration of Magisk) =>
https://xiaomi.eu/community/threads...nstalling-android-11-update.60181/post-594671
2) Install
* this workaround in Magisk app =>
Fix_CTS_SafetyNet_v1.0-Magisk.zip (This Magisk module will change the model name of your device to "Xiaomi device")
(*) = In Magisk app > Tap on "Puzzle" icon (bottom) > Tap on "Install package from storage" button (top) > Select the Magisk module (zip file) > Install > Reboot
NOTE: After that, it's recommended to Clear all data of "Google Play Store" , "Google Play Services" and "Google Service Framework" apps in phone's settings** then reboot your device.
(**) = In Settings > Manage Apps > Apps > Be sure to enable "Show all apps" (or "Show system apps") option in "3-dots" menu (top-right) > Search wanted app and tap on it > Clear data > Clear all data