Ok so I have been down and back with Support since the release of iOS 15 (contacted them day of release and been in contact since) and here's what we've found. If you ignore the message, PLEASE READ THE LAST TWO PARAGRAPHS. It's a call to action that needs to be done so Apple will prioritize this issue.
When the podcast app is force closed or is booted from the RAM (timed out due to not being used), the Playing Next queue mysteriously disappears. I use the word "disappears" because it's not technically gone. If you try to play a new podcast episode, it'll ask you if you want to resume with your queue after finishing the episode or clear the queue. That's because the queue still "exists".
So the podcast app timed out for the millionth time and your queue is gone again. Pick some random podcast episode and add it to the queue (either play next or play last, really doesn't matter) and boom, your queue with everything that you added to it previously will reappear. Every time this happens to me, I just add a random episode as "play next" and then go into the queue and delete it (I add a TON of episodes in advanced so this still saves me a ton of time).
The other weird thing about this is when doing the above trick to get the queue to reappear, if this is the first time you did it since that current episode has been playing, it will appear as a duplicate in the queue (like if you're listening to X episode 48 and it times out, you get the queue to reappear, and X episode 48 will show as the next show to play in the queue even though you're listening to it right now). Dunno why that happens but just be aware and delete it when it reappears in the queue. It's always next or second if you added a show to play next in the queue so it's easy to find and isn't hidden.
Support sent it to engineers and they pushed back saying they no longer work on Apple Podcast app. If you report the issue to Apple Support, NOTHING CAN HAPPEN. For everyone who is suffering from this issue (should be everyone), you have only two ways to report the issue that will actually be heard for it to be worked on. The first way is in the podcast app, go to any show or episode of a show, tap the three dots, then tap on "report a concern." Feedback type is "Broken Feature" and for "Broken Feature" I put other (seeing as the issue is the "Playing Next" queue, not the "Listen Now") and report it there. The second way is to go to the website on a browser (Apple's site /feedback) and under services, select Apple Podcast. It'll take you to the same place the app takes you. Make sure to use feedback type "Broken Feature"
The support agent made it clear they have no way to report the issue as their teams don't work on the Apple Podcast App anymore so everyone please report the issue using the method above. This is the only way they'll listen and actually prioritize/work on this issue. Also this will be where you report Apple Podcast issues in the future.
