Avoid using Xiaomi 11 ultra in Canada. Frequency bands are not available and LTE/5G speed sucks

I would even suggest customers not to use devices that wasn't destined for Canada market if they want to use all  Koodo cellular service features. For example, VoLTE and VoWifi is likely incompatible with those devices 

In North America, you are generally safe if you limit handsets to relatively recent:

• Bell
• Telus
• Rogers
• T-Mobile
• AT&T

To be avoided:

• Verizon
• Sprint

Coming down the pipe in Canada is mandatory VoLTE like the US currently has. It’s a bare minumum for any roaming to work in the US at all.

Keep in mind that phones sold in the US are NOT generally unlocked and that the original carrier must grant permission. On the other hand, software updates on US carier-sourced phones will be more frequent and up-do-date as long as you have an original SIM.

Yes, I learned this hard way.
I am able to use Volte and Wifi calling but freqeuency bands are so limited in these devices, can’t even enjoy 5G at all.

To be fair, Koodo has not rolled out 5G just yet. Though your phone does support one band of 5G, provided mobile providers like TELUS support band n78. Agreed. There are  a lot more 5G bands out there. Other than that, the network specs for this phone are fully compatible with Koodo.

Yes but I tried sim card of bell as well in this phone. Unable to cross 80 mbps with 5G and 50-60 mbps in 4G.
I might will sell it move back to pixel.

Which variant of it do you have? There’s slight differences between the China, Global, and India submodels. I see that you said VoLTE and wifi works, so what’s the issue? 

I have Chinese variant. Ordered from https://www.giztop.com/
I’ve always used Huawei but after ban, android market is limited to samsung I think.

I’ve used Xiaomi, never had issues. It could be a lemon phone with something wrong with the network chip or antenna. You’re governed to 100mbps with Koodo, so 50-60 is still quite a bit below that but I’m usually all over the place with data speed with a samsung device. The 11 ultra should have the latest LTE protocol. I did some quick reading, and the China variant may have speed limitations in North America with some sort of bandwidth limit? I’d have to research more but that could explain it. I have always used global variant xiaomi phones, so maybe that’s the difference here. 

Thanks for your reply.
Yes, it seems like Chinese Variant thing. I wish we can unlock frequency bands.