I am happy to report that after troubleshooting this issue, I have found a solution. To sign into my Google/YouTube account, I changed the web browser that I was using, to sign in. Originally, I was using Internet Explorer 11, on Microsoft Windows 7. I found some troubleshooting articles on Google, urging users to try a different browser. So, not only did I change browsers, I changed platforms. I used a virtual machine, consisting of Solus Linux (https://solus-project.com) and the latest Firefox browser, Version 57. The sign in worked, perfectly and I am happy to report that my Samsung Smart TV's YouTube application is working, perfectly, once again, with my new Google/YouTube password.
I hope this post helps others who may find themselves in similar situations. Thank you to all who helped me.
Samsung UN55HU8550 (2014 Smart TV) is completely up-to-date, including system firmware and all downloaded applications. YouTube was working, fine and signed out of it, to change my connected Google password. Now, when I try to re-connect my Samsung's YouTube application to my Google/YouTube account, while on the connect the device webpage, via Google, the webpage window simply sits at connecting device. Yet, the Samsung Smart TV never connects to my Google/YouTube account. I have removed and re-installed the YouTube application (on the Samsung Smart TV) and I still cannot get my YouTube application to re-connect to my Google/YouTube account.
Is anyone else experiencing this? Can someone please offer helpful suggestions? Any help is greatly appreciated. Thank you!