Parse error for CISA feed

I’m getting a parse error for the following site but it seems to be working properly when I use a browser to view the feed. Any help is greatly appreciated.

https://www.cisa.gov/cybersecurity-advisories/all.xml

Looks like their servers are blocking NewsBlur. I reached out with this email:

Hi, I run NewsBlur.com, an RSS reader, and one of my users mentioned that your RSS feed stopped working on February 24th. We just changed hosting providers and now have a different set of IPs. Our IPs are being blocked (HTTP 403). I’d like to request that they are unblocked. Here is a handy list of IP addresses that we use: https://www.newsblur.com/api/ip_addresses/. Happy to answers any questions!

Here is the RSS feed that is blocking our RSS crawler: All CISA Advisories

Sam

Thank you very much for your quick reply! Love Newsblur! Hopefully they respond soon.