Adding podcast by URL gets no response

I have a paid podcast with which I've been having problems for the past few months. Intermittently it fails to load new episodes and I have to delete the podcast, refollow by URL, and then go in and manually re-delete hundreds of episodes. Tedious and annoying, but workable.

However, this time, when I go to refollow by URL, I get no response at all. No error message, no login, no podcast, nothing. I've tried doing it by copy-paste and manually, on my iPhone and on my MacBook Pro, with the same total lack of result every time. I've found answers in this community for what to do about various error messages, but not what to do when there is no response whatsoever. What should I try?