Does anyone else in your area with Koodo/Telus have the same issue? Can you try the sim card in another phone to confirm that the problem follows?
Yes, I can try that later today. Thx!
Then we can proceed from there on how to go forward.
I had a similar issue where it went robotic sometimes, and cut out too at about the same intervals.
I have the iPhone XS, and as it turns out that phone with VoLTE turned on (Cellular → Cellular Data Options → Voice and Data → VoLTE (on) was the problem for any network I tried (Freedom, Koodo). Only problem is Koodo, Telus, Bell, now hide the option because they want everyone to use VoLTE (and retire 3G like the US has done). Rogers, Fido, Freedom SIM cards still show the option.
You can change your network to 3G on Koodo to see if it gives you better voice quality (no cut-outs or robotic voice), but then you get slower data speed (compared to LTE).
In the end (in my case) it seems to be the phone itself. Some iPhone XS seem to have this problem, and I’ve heard iPhone 11 Pro and iPhone 12 Pro can have VoLTE issues too (when reading the Apple forms and showing all replies)
My girlfriends 11 Pro seems to work fine on Koodo VoLTE so I’m going to use her phone and she will buy a new one.
The Apple store may be able to fix your phone (for a price) if you can prove multiple networks have the voice quality issue.