I have Spotify Free on my iPhone 5 as well as my MacBook Pro.
Recently I was searching through the podcast area for anything of interest. I found two podcasts that seemed interesting at the time but in hindsight I don't want to listen to them. I see that they appear in the Recently Played section of the Home screen. These two podcasts also appeared in the Recently Played section of the desktop app.
I wasnt to remove these podcasts from the Recently Played section of my iPhone but I have yet to find anyone who talks about this on the 5. There are several articles about removing thins on the iPhone 7, but the app looks toally different.
I was able to remove the podcasts form the desktop app, which is good, but the syncing process does not appear to work from desktop the iPhone 5.