Legacy Bluetooth Setting
On some Android phones, you may need to enable Legacy Bluetooth settings in order to connect older devices.
Once you sign in, if you click the three-dot menu and then go to Options and Audio, at the very bottom, you'll see an option for Legacy Bluetooth mode.
Auto: Zello will try to connect using what it thinks is the best method possible
On: Zello will always try to connect using Legacy Bluetooth Audio
Off: Zello will never try to connect using Legacy Bluetooth Audio.