@darmitage.
I'm glad to hear that your number is working well within the US. For the issue with calls from Panama, it could be related to international calling restrictions or carrier-specific limitations. Since the person is using a US cellphone, it's possible that their service plan doesn't support international calls or there might be a need to enable international calling with their carrier.
To ensure that the issue isn't on the VAPI side, please check the following:
1. Verify that your VAPI number is set up to receive international calls.
2. Check if there are any restrictions set in your VAPI dashboard that might be blocking calls from international numbers.
3. Review the phone calling guide for any additional settings that might be relevant for international callers.
If everything seems to be configured correctly and the issue persists, it may be best to contact the individual's mobile carrier in Panama to ensure that their plan supports international calling to the US. If you need further assistance or have any other questions, please let me know!