Initially, problem I had was, when listening to SYSK (Stuff You Should Know, feed address https://www.iheart.com/podcast/105-stuff-you-should-know-26940277/ ), listening to files I’ve already downloaded triggers a flood of data while on wifi.
At the same time, the podcast cover never properly loaded.
Turning off data over mobile stopped this while on mobile, but did not stop it while on wifi and playing a podcast, to the tune of hundreds of MB over the course of a listening period, definitely not trivial, plus it drains the battery.
What seems to be the trigger was that I had “Disable mobile data” enabled on Android. Presumably, the episode cover refused to load properly on wifi, but it would keep trying and trying, downloading who knows what while listening to the same podcast.
Re-enabling mobile data quickly allowed episode cover on wifi and stopped the weird download behaviour, even if I did “Disable mobile data” again.