@Islander which device model would you be using? There's some basic level troubleshooting that the community might be able to help with but we'll need a few more details.
Also, as obvious as this might seem, are you connected to Wi Fi during these calls? If not, connect to Wi Fi and try again.
Extend is still in beta testing so your best bet might be to contact the dedicated beta support team via: 1-866-558-2273; you'll then get an option to select "TELUS Extend" as an opotion.
Thanks for trying TELUS Extend and providing your feedback! Sorry it's taken so long for us to get back to you.
The experience you described is commonly associated with using TELUS Extend while in a poor coverage area. We are aware of this, and are working on finding ways to optimize client experience prior to the public release of TELUS Extend. Thanks for your patience.