Having trouble using my Mix3 with canadien sim card

[moonlenjoe]

I am in Quebec, Canada now and bought my Mix 3 from China. I can only use 2G data with any of the local sim cards, while 4G+ with my chinese sim card.
Having no idea why...

I tried to flash an EU Rom but it kept reporting "can't upgrade from an unofficial Rom package". But the Rom package was downloaded from here.....

Need help plz....

 

[cobben]

You have to unlock your bootloader and install TWRP before you can flash an eu rom.
You have some reading up to do.

Take a look at this thread, might be similar.

https://forum.xda-developers.com/mi-mix-3/help/network-connectivity-issues-t3884384

 

[moonlenjoe]

You have to unlock your bootloader and install TWRP before you can flash an eu rom.
You have some reading up to do.

Take a look at this thread, might be similar.

https://forum.xda-developers.com/mi-mix-3/help/network-connectivity-issues-t3884384

Thx, man