Detective Work
We've made some progress figuring out why many paying supporters aren't seeing the bonus content in their feed, and it's because many podcast apps make the incorrect assumption that because many of the episodes in both the normal/non-Patreon feed and your personal Patreon feed have a similar title, author, and image, that they are duplicate feeds, causing them to ignore your custom feed entirely.
With the podcast industry's focus on listener engagement and support, you should expect to see this issue quite a bit in the future, and I wonder how creator's of these apps will handle this type of problem.
In response, we've added some tags to your private Patreon RSS feeds that, in theory, should help the badly behaving apps from continuing to erroneously block you from getting the episodes you're expecting.
It may take a little time (A day? A week? ...we have no clue how long these misbehaving apps may have decided to cache your feed) before you see the bonus content appear in your feed, so please be patient and let's all see together if this change works.
Special thanks to Listener Ethan for doing the detective work on this issue!