Laravel Middleware Class does not exist

I am trying to solve the problem below 3 days and with no success.

I created a middleware to change the CMS language. The problem is that the middleware class is not being found.

I have tried the following solutions: "I've already confirmed the file name and class name. They are identical. - I've already run the dump-autoload composer command inside the project folder

Thanks for the help.

via Chebli Mohamed