Does iTunes occasionally re-download podcast content during playback?

I play podcasts during work, where my internet connection is hotspot with a 5Gig limited data usage.

I've been downloading podcasts on my wifi at home so that I don't have that usage on my hotspot.

I've been trying this for a month and my usage has increased and I can't figure out why, except that occasionally I will have to pause the podcast or the podcast will hitch and say "connecting to URL" which makes me think it's downloading the content again.

Am I correct? Why? What can I do to stop this or work around it?

Please advise, thank you.