Pro Sites Signup Page Not Working

So, this MU site I'm working on had a development temporary domain in the initial stages of development. At that time, I set up Pro Sites, package levels, a blog template, plugins, etc.

Everything at that time worked just fine. Then, yesterday, we got approval on the actual real domain we were going to use so we switched to it. We configured the wp-config.php, server stuff, DNS, SQL site URLs, etc.

Now, everything is functioning as it should, with one exception. The Pro Sites signup/management page.

When you try to navigate to it, it simply times out because of too many URL redirects.

Can you please let me know what I may be missing here or can you check it out yourself? Please note that I changed the default URL of this signup page to "/pl-local/", but I did this before the domain switch and it was tested and working.