Contacting package repositories very slow

[Madison Smith]

M-x package-refresh-contents
take several minutes to finish, when it finishes at all.
While it is running, the message "Contacting host: melpa.org:443" is
displayed continuously. Why might this be?

I am on GNU Emacs 27.2

Running C-h v package-archives outputs
(("melpa" . "https://melpa.org/packages/";)
 ("gnu" . "https://elpa.gnu.org/packages/";)
 ("org" . "https://orgmode.org/elpa/";))
and running curl -I on each of these URLs yields  "HTTP/1.1 200 OK" in
under a second, which makes me think that contacting the host can't be the
actual problem.

Thanks for your thoughts.