The . suspect that it are 2 nested resources. (See php artisan route:list )

If you use the / Route::resource('chalk/board', 'ChalkboardController'); You will see that you have a chalk/board url with the name board.index.

If you want to have the chalk.board.index as name as well the other names you have multiple options:

1: use the names function:

Route::resource('chalk/board', 'ChalkboardController')->names([  
    'index' => 'chalk.board.index',  
    'store' => 'chalk.board.store',  
    // and the create, update, show, destroy and edit  
]);

2: Use the name function for each route:

Route::resource('chalk/board', 'ChalkboardController')  
    ->name('index', 'chalk.board.index')  
    ->name('store', 'chalk.board.store')  
    // and the create, update, show, destroy and edit  
;

3: Put it in a group with a name:

Route::name('chalk.')->group(function () {
    Route::resource('chalk/board', 'ChalkboardController');
});