I run Pi-hole on my home network. Its default blocklists has prevented several podcasts in my partner's Podcasts app from playing. I've had to explicitly allow a couple of distinct third-party trackers/analytics services for them to play.

It was news to me that what I thought was a simple audio file also came with a bunch of analytics/tracking. I previously thought analytics were limited to simple events (play, pause, subscribe, finish, etc.) collected on Apple's side, but apparently not.