Reddit forum feeds not updating (rate limit?)

This seems to be causing a problem with RSS feeds for specific posts.

E.g.: Post: https://old.reddit.com/r/PostgreSQL/comments/1ucs1ap/multitenant_saas_architecture_postgresql_schema/

with feed: https://old.reddit.com/r/PostgreSQL/comments/1ucs1ap/multitenant_saas_architecture_postgresql_schema/.rss

When added to Newsblur seems to get the feed for the entire PostgreSQL reddit instead: https://old.reddit.com/r/PostgreSQL/