[Bug]: Country Code Resets to Empty String After Phone Number Update

[jmargielewski]

Bug Report: Country Code Resets to Empty String After Phone Number Update

Description

When selecting certain countries (notably US/GB), the countryCode in MuiTelInputInfo resets to an empty string after updating the phone number, despite initially being set correctly.

Steps to Reproduce

1. Initialize MuiTelInput with any default country
2. Select UK (or other affected countries) from the country selector
3. Enter a phone number
4. Observe the countryCode in the onChange handler

<MuiTelInput
  onChange={(value, info) => {
    console.log('Country Code:', info.countryCode); // Initially 'GB', then empty string
  }}
/>

Expected Behavior

• The countryCode should remain consistent ('GB' for UK) throughout the component's lifecycle
• The country code should not reset to an empty string after phone number updates

Actual Behavior

• The countryCode is initially set correctly ('GB' for UK)
• After updating the phone number, the countryCode becomes an empty string
• This causes UI flickering and inconsistencies in country code display

Environment

• Library Version: 9.0.0
• React Version: 18.3.1

Impact

• UI flickering when country code is displayed
• Inconsistent country code tracking
• Potential issues with form validation or country-specific logic

[babajaga3]

Not sure if it's consistent, but from what I have experienced, this occurs only when formatting is enabled (i.e. disableFormatting={false}

[raldred]

Happening for us regardless of disableFormatting true | false when we toggle the country from any other countries to any +1 country
it resets to our defaultCountry GB

Version 8.0.1
MUI 6.5.0
React 18.3.1