Garmin Speed Sensor 2

Good Morning. I am finding that my speed sensor although connected to my iPhone via Bluetooth is not reading on Zwift. Also I have been trying to complete the initial ride several times but it keeps crashing before I can finish. When I restart and it ask me to continue I press yes but there is no data recorded on screen and my rider doesn’t move. Please help as I love the idea of this app to help me train during lockdown and beyond. Thanks I’m advance.