I use RSS-Bridge for creating some RSS feeds and I have it behind an htpasswd. When I try to add the feed to FreshRSS with the login details, I receive "Unknown error for feed" in the log. If I enter the wrong password, it gives "401 Unauthorized" as it should, so it seems login is working correctly.

However, if I disable htpasswd on the site so that no password is required to access it, I am able to successfully add the feed to FreshRSS - no errors. The issue is only occurring when using a password.