After 25+ years with Rogers, I am leaving fido because they blocked my new samsung 9 phone from wifi calling. The reason... I didn't buy my phone from them.
Dont switch to fido if wifi calling is important to you!
Welcome to the community!
It is stated on the website if you have a non-Fido Android phone WiFi calling will not work.
Taken from here.
With that being said personally I have not seen a non-Fido Android phone of the same model that they carry not work. I personally had a Galaxy S9 that was not purchased from them and it worked. Have you tried reaching out to customer service and see if they can add your IMEI number and see if that helps? Some customers even got it working after speaking to a technician. What is the exact model of your phone?
You can also try changing the CSC of the phone to Fido and see if it helps, you can find info on doing that here.