I also had this problem during the first installation after the bootloader unlock. The solution was to reinstall the original CN ROM and then reinstall xiaomi.eu with First Install.
I have the same issue. I try to start the TWRP from Updater, from the power off menu and with Power on and volume +. The result is the same. The last weeks no problems.
K30Pro
There are still problems with DUAL apps. File manager and some apps FC. I have no problems without DUAL apps. Is there any solution to this problem? Otherwise good update.
MI MIX 3
Good update.
Really smooth and fast.
No bugs found yet.
And the best for me is: There is no new LR TWRP installed with the update 20.1.16.
Thanks to the team.
Enjoy your holiday