Hello, Sir.
As an experienced Wordpress developer, I can say that this problem is usually about jQuery/javascript. These form usually send requests via AJAX, then get response and if it success, it will log user in. But for some reason, there's no response or the response is not succeed so it just say "Please wait".
So, please contact me so that we can discussed and I can start solving this problem for you.
Thank you very much for your time and consideration.
Tuan Hoang