My Mi 9 6/128 Global Version works fine aswell.
I had Miui 10.2.35 China Stable installed via MiFlash. When i installed 9.9.26 i formatted Data and Wiped Cache/Dalvik.
Then i dirty flashed 9.9.27 and wiped Cache/Dalvik.
I have no Problems so far, but i can't test Dual Apps at the moment.
Dirty Flash 9.9.27 over 9.9.26, wiped cache/dalvik after install.
I still can't select Google Assistant as default Voice Assitant to use with the AI button, but since i use Mi Ai i don't really mind.
Everything else seems to be working fine.