After creating a Registration in the back end, we go out to the front end to grab the URL for our newly created registration. We then paste the URL into a content article.
When the link is clicked from a content article, it appears to ignore the cutoff date as well as the Max capacity.
However, we do not have this problem when trying to register for an event from the Front End (option=com_dtregister).
No, the cut-off date is presently calculated in the creation of the urls in the component and module. If you copy and paste the url to somewhere else, you are using a url that has already passed the cut-off check.
Correct. As I said... the links you are using will not check the cutoff because those urls were created by the component after having already checked for the cutoff. The component page will check the cutoff and it works fine. The problem for you is the manually created links. There are NOT going to check the cutoff. The component, plugin and module automatically check things like the cutoff but your manual links will not. It is not setup that way.