Hello. Thank you for contacting the Toolset support.
Our systems team checked and they find that there were many requests were made and hence system found it as its spamming the api hence your domain has been blocked. Its unblocked now.
That corrected the issue again, thanks. The Installer System status page is indicating it can connect to the API server now. Can you confirm that this is a block that keeps happening on everything under *.unc.edu? Our department runs our own sites (about 40) outside of the main UNC web infrastructure under subdomains of fpg.unc.edu. I can't imagine there is enough traffic just from us to look like spam. But UNC itself has hundreds, if not more, WordPress websites and I think most use toolset. Is there any way to permanently keep this from happening again? I can try to reach out to people in our central IT if there are recommendations for how they configure things that might make a difference. Let me know if the systems team has any advice.