no signal 438xxxxxand 514xxxxxx

Restart your phone with the fizz sim card, check that your service is up and running on your control panel, if not contact fizz support

Make sure your APN is correctly configured.
https://fizz.ca/en/faq/what-are-fizz-network-settings-apn

What type of phones do you have? Are they fairly recent models? Fizz runs on different frequencies than those of Fido's.

What type of phones do you have? Are they fairly recent models? Frequencies are different and if your phone would not work with Videotron, it won't work with Fizz.

You just transfered your phone from FIdo and the transfer process has not completed yet.
It may take several hours.

IF you just port your number, wait up to 4 hours and wait it's ported. Then you can use your Fizz sim.

when you change to fizz it takes time for the line to transfer you just need to wait a few hours and it should work