@types/react@18 removed implicit children prop from type React.FC, from now on children should now be explicitly defined.
DefinitelyTyped/DefinitelyTyped#56210

From a quick exploration; extending BoxExtendedProps instead of BoxProps on affected components should resolve the issue :)

Expected behaviour

Allowed to pass children props when using React 18 and TypeScript.

Current behaviour

TypeScript complains that Property 'children' does not exist on type X.

https://codesandbox.io/s/fragrant-waterfall-6921n6?file=/src/App.tsx

Steps to Reproduce

Create a new project with React 18, @types/react@18 and TypeScript.

Your Environment

• Grommet version: 2.22.0
• Browser Name and version:
• Operating System and version (desktop or mobile):