I had this struggle with double notifications in Pocket Casts. First, I seemed to have found a solution by signing out and into my account again, but after some time the pair-wise notification were back.
Tired of this issue, I eventually deactivated notifications within Pocket Casts. After that, you’d expect that notifications would stop popping up altogether going forward, right?
Here’s the thing: I still got notifications, only the notifications din’t come in pairs any longer. Weird.
OK, time for more radical measures. I deleted the app, and reloaded it from the App Store. Unfortunately, I did not even make it to the first notification when I realized that the audio effects were simply not available.
The buttons were just inactive, and it was not possible to use these features. This was no good.
After taking a deep breath, I was willing to give it one additional shot. If that worked I would stay with Pocket Casts, otherwise it would finally be time to leave.
Again, delete the app. Reload. Launch. Try audio effects. Wait for incoming notifications. Phew.
The tentative conclusion is that the last install seem to work according to my expectation. However, I have to say that this job stretched my loyalty to the product dangerously close to the snapping point.