• miflash to flash international rom
• unlock bootloader again
• flash twrp
• flash xiaomi.eu and magisk

1. Unlock bootloader via http://en.miui.com/unlock/
   • hold volume down and power button
   • use the unlock tool to unlock
2. Install twrp in fastboot mode
   • fastboot flash recovery rom\twrp-3.3.0-1-mi6.img
   • fastboot boot rom\twrp-3.3.0-1-mi6.img
3. in twrp mode, push rom file to android
   • Go to Wipe > Advanced Wipe and wipe Cache, Dalvik Cache and Data.
   • adb push rom\xiaomi.eu_multi_MI6_V10.3.1.0.OCACNXM_v10-8.0.zip /tmp/
   • adb push rom\Magisk-v19.0.zip /tmp/
4. use the install button in twrp
5. Wipe Cacha / Davlik and reboot system

• delete google pay data
• remove /data/data/com.google.android.gms in twrp
• re add card

https://xiaomi.eu/community/threads/google-pay.49986/

ref: https://www.reddit.com/r/Xiaomi/wiki/twrp#wiki_instructions_for_clean_installing_in_twrp