Chinese rom (if you get a black screen earlier) then you have to upload this rom with XiaoMiFlash
http://bigota.d.miui.com/8.11.15/tiffany_images_8.11.15_20181116.0000.00_8.1_cn_6ea7e322a8.tgz
******= b i g o t a (written together)
and now i install 8.12.13 eu...
I used this twrp 3.2.2 for my mi 5x and passed (but make yourself a copy of the system).
https://forum.xda-developers.com/mi-5x/development/recovery-twrp-3-2-3-treble-t3836229
I changed from 8.11.1 eu to 8.12.6 (but I also missed the drivers - I got a black screen and I had to send Chinese rom...
I used this twrp 3.2.2 for my mi 5x and passed (but make yourself a copy of the system).
https://forum.xda-developers.com/mi-5x/development/recovery-twrp-3-2-3-treble-t3836229
Wipe cache and dalvik does't work, and Clean install can't do it now, because I do not have enough time :) What hardware versions do you have (I have V1), maybe it depends on it?