[5.x]: GraphQL mutation for nested elements does not accept entry titles

[AugustMiller]

What happened?

Description

Steps to reproduce

Execute a GraphQL query like this:

mutation MyMutation {
 save_tours_tour_Entry(
   title: "Test from GraphQL!"
   stops: {
     entries: [
       {
         stop: {
           destination: [8],
           highlights: "First stop!",
           id: "new-first"
         }
       }
     ],
     sortOrder: [
       "new-first"
     ]
   }
 ) {
   id
 }
}

Craft will produce an error like *Title* cannot be blank.. If you provide a title key in the stop hash like this…

stop: {
  title: "Example",
  destination: [8],
  highlights: "First stop!",
  id: "new-first"
}

…a new error is emitted: Field "title" is not defined by type stops_stop_MatrixEntryInput.

Craft CMS version

5.0.0+

PHP version

No response

Operating system and version

No response

Database type and version

No response

Image driver and version

No response

Installed plugins and versions