I have redmi note 9 pro max phone supporting 4g network still I received mail that you are using 3g network and you will be charged $3 after may 4th 2025.
Here i am attaching my phone screenshot where you can see it is using LTE
Hello Fido_1,
Welcome to the community!
I understand you have selected Prefer LTE network on your device. However, are you certain your device is actually connected to that network?
As far as I am aware, these are the bands/frequencies for that particular device:
GSM：B2/3/5/8
WCDMA：B1/2/5/8
LTE FDD：B1/3/5/8
LTE TDD：B40/41（2535-2655MHz）
~taken from here.
According to those specifications, that device would only have one compatible LTE band/frequency. You can verify the compatible bands/frequencies here. Coverage would depend on your location relative to the cellular towers. You can get an idea of your surrounding towers here. That said, it's possible there are different versions of that device and your variant may include a greater number of compatible bands/frequencies.
Assuming your device is able to regularly connect to the LTE networks, connecting to that network may only be a part of the issue. Fido traditionally have not supported certain services (ie voLTE and/or Wifi-calling etc) on devices or versions of devices they do not sell. Though, that does not necessarily mean people had to purchase from Fido. Fido sells the same Canadian versions of devices as the other Canadian mobile providers as well as local box stores etc. As long as the device was the same version as the one they sold, it was possible for those services to be supported.
On the other hand, non-Canadian versions of devices (ie US or Global Samsung S series etc) would likely not be supported for those services. In addition, other devices from manufacturers which are not generally sold from Fido or Canadian mobile providers (ie Xiaomi, OnePlus, Oppo, etc) are also likely not to be supported for those services (see here, here, here, here. etc).
Currently, all devices regardless of where they were purchased or from what Country can use the UMTS/WCDMA network for calls and messaging (provided the device has compatible band/frequency). They can also access the LTE network for data (provided the device has compatible bands/frequencies). That would be the reason you currently may be able to fully use your services.
However, even if your device connects to LTE, it currently will likely not be able to avail of voLTE or Wifi-calling. Without voLTE, calls and text messages (SMS and/or MMS) would fall-back to the '3G' network. Unfortunately, once the '3G' network gets decommissioned (July 2025), that device will likely not work for calls and/or messages anymore. I understand that once the '3G' network is decommissioned, limiting voLTE to only Canadian versions of devices they sell will be problematic for other device users. However, I am not aware of any official stance from Fido or Rogers on the matter.
Hope this helps 😀
Cheers
