Hack/workaround for this issue: https://github.com/barryvdh/laravel-debugbar/issues/405#issuecomment-166698699

ConfigServiceProvider.php

<?php

namespace App\Providers;

use Illuminate\Support\ServiceProvider;

class ConfigServiceProvider extends ServiceProvider
{
    /**
     * Overwrite any vendor / package configuration.
     * This service provider is intended to provide a convenient location for you
     * to overwrite any "vendor" or package configuration that you may want to
     * modify before the application handles the incoming request / command.
     */
    public function register()
    {
        if (! $this->app->environment('production')) {
            $this->registerLocal();
        }
    }

    /**
     * Overwritten items only on local environment.
     */
    protected function registerLocal()
    {
        if (env('APP_DEBUG') && env('APP_DEBUG_BAR', true)) {
            config(['debugbar.enabled' => true]);

            // Disable if using BrowserSync
            if (strpos(request()->root(), ':') !== false) {
                config([
                    'debugbar.collectors.default_request' => false,
                    'debugbar.collectors.symfony_request' => false,
                ]);
            }
        }
    }
}

Note: This hack is no longer necessary.