It seems like this could be a session-related issue. How is your session configured in the .env file? If the session driver is set to "file", make sure the correct permissions are applied to the storage directory. You can set them using the following command:

chmod -R 775 storage

Also, ensure the correct owner and group are assigned to the directory.

For Backpack, it's crucial to have the APP_URL setting in your .env file configured correctly. Verify that it matches the URL you use to access your application.

After making these adjustments, clear and optimize your application's cache by running the following commands:

php artisan optimize:clear
php artisan basset:clear
php artisan optimize

If the issue persists, check the Laravel error logs (storage/logs/laravel.log) or your server's logs for more details.

Cheers!