Hello williamssa2,
Thanks for reaching out to Apple Support Communities. I understand you’re having issues with your audio switching to a Bluetooth device during a call. I’ll be happy to help with this.
Apple has info on how to bypass your Bluetooth device for calls. 'To use the iPhone receiver or speaker for calls, do any of the following:
- Answer a call by tapping the iPhone screen.
- During a call, tap Audio, then choose iPhone or Speaker Phone.
- Turn off the Bluetooth device, unpair it, or move out of range.
- Go to Settings , tap Bluetooth, then turn off Bluetooth.'
You can read more about this here:
Connect Bluetooth devices to iPhone
Another option would be disconnect from your Bluetooth accessories from Control Center. 'When you toggle the Wi-Fi or Bluetooth buttons in Control Center, your device immediately disconnects from Wi-Fi and Bluetooth accessories. Both Wi-Fi and Bluetooth will continue to be available, so you can use important features.' Take a look at this article for more details:
Use Bluetooth and Wi-Fi in Control Center
We hope this helps.