Purchased Xiaomi Mi Max 3 with Xiaomi.eu ROM pre-installed (https://tradingshenzhen.com/en/mi-max-3/1302-mi-max3-6gb-ram-128gb-rom-snapdragon-636.html)

Tried to get settings/data/apps transferred from old phone to new, but none of the Google set up prompts appeared on boot.

The following process will get it to work (hint: OpenGApps)

  1. Download two items to phone -  1) Most recent ROM 2) OpenGApps
  2. Flash phone with most current ROM - link (download to phone, reboot to TWRP ( Volume Up + Power), install ROM)
  3. Flash phone with OpenGApps
  4. Boot phone - if you get stuck in the boot logo, power-off and power-on again
  5. Once booted, you'll now see the Google Set Up prompts