[BUG] custom component not able to enter default value

[ghost]

Environment

Please provide as many details as you can:

• Hosting type
  • [ ] Form.io
  • [x] Local deployment
• react-formio: 4.2.3
• Frontend framework: react 16.8.6
• Browser: Chrome
• Browser version: last

Steps to Reproduce

I try to add a custom component as you can see on code sand box. The custom component is displayed, but i would like to have the possibility to config the default value in the form builder pannel configurator.

Expected behavior

Here is a toggle, and i would like to have the possibility to put true or false.

Observed behavior

nothing to introduce default value when it's a custom component.

Example

https://codesandbox.io/s/react-xqs2u?fontsize=14&hidenavigation=1&theme=dark