Might there be problems with IPv6-dual stack lite-connections?

Hi,

like some others I experienced various problems with the Team Treehouse-page. Either the next video doesn't get loaded or the quiz or the code challenge don't get evaluated. So I can not keep on working through the course. After I checked if my browser, my bandwidth and my connection to the internet are okay, I even paused my subscription, cause I can't use the courses that way. Now I just came to an other guess what might be the problem. I've got an cable landline based on IPv6-dual stack lite. That means: I've got an individual IPv6- but not an individual IPv4-address. My IPv4-address is an address from my ISP that I can use via a NAT-like-structure and all my connections to IPv4-addresses get tunneled through IPv6. There are more and more internet-connections like this from day to day. So might it be, that the servers of Team Treehouse have problems to connect with users behind such a connection, since Team Treehouse still completely depends on IPv4?