There are around 15 different kinds of things that can be Favorites and under the hood they are all quite different. Can you give an example?

Under “My Sonos," there are a variety of listings for stations etc. to be saved as favorites. I most often use presets I have saved under “Stations." But this problem also occurs when I click on an icon under the "recently played" items. In short, virtually anything I try to play from the app by touching the appropriate logo has a failure rate above 70%.

Ah, Recently Played is very different to Favorites, the former is much fussier.

For Favorites that are radio stations, a url is saved, and sometimes those urls will quit working when a station changes it. These are fixable by re-favoriting it from the source service, which will update it.

Recently Played on the other hand is, frankly, a it of a mess. When an item is Played, its details are saved in a cloud database, but it is quite easy to play an item “incorrectly” in such a way that it will play ok right then, but not work when later selected for playback. This is especially true if playing items from outside the Sonos app itself.

I do not believe it is a URL problem on the favorited stations. If you keep pushing the icon after it delivers a bad station, the right one will eventually play. Sometimes it takes two attempts, sometimes three but eventually works. And, yes, I pretty much gave up on recently played.