My RSS reader, Thunderbird, is suddenly throwing errors on all my ani.social feeds (communities, inbox). Trying to verify the URLs through the feed subscriptions window I get a "The Feed URL is not authorized." message.

Looking at the error log, it's complaining about not well formed XML and clicking on the link results in an attempt to complete a Cloudflare "Verify you are human" challenge.

I'm not getting these issues on any other instances. RSS getting blocked like this is the reason I left Reddit for Lemmy in the first place.

Might be an usage rate limit? Try to wait a little and also set Thunderbird to check a bit less frequent.

The feeds are currently set to check once every 100 minutes (Thunderbird's default setting). Is there a recommended frequency I should be switching to?

If my rate limit theory is correct, I think it'd depends on how many feeds you're pulling. For a handful few, 100 minutes sounds in my experience. For 1000+, just refreshing might cause timeouts.

Sorry about that. I've been tightening the bot challenge rules because of the amount of bots scraping the site lately. I exempted /feeds so please let me know if it's working for you now.

Feeds are validating now. Thanks for fixing it!