Downloaded podcast will not play unless connected to cellular network. Why. How much data am I using

I subscribe to a number of podcasts. To save data charges; Settings > Podcasts > Block Downloads Over Cellular is switched ON and Cellular Data is switched OFF. Under Settings > Cellular > Podcasts is switched OFF - so podcast downloads only happen at home over WiFi.

When I’m listening to the downloaded podcasts away from WiFi and Cellular Data OFF some podcasts allow Pause, Skip Forward and Skip Back, while with other podcasts when I try to Pause, Skip, etc. I get a dialog popping up saying “Cellular Data must be ON to listen to podcasts” and the podcast won’t start playing again - unless I turn on cellular data for a moment, tap play on the podcast to get it started, then switch cellular data off again.