So without having looked into it really, my assumption is that these podcast hosts will serve a specific file based on the response to an API call. If my Pihole blocks that call, they don't want to serve nothing, so they fallback to a file that sometimes has "generic" ads (often for US-based companies) or other times no ads at all. Of course this doesn't work for all podcasts, and as mentioned sometimes still has ads anyway. One day I might look more closely into it.
Because a lot of podcast networks have dynamically inserted ads that change based on your geolocation, I've found that my Pihole can often provide a feed without any ads. I assume it's like a fallback in case the geolocating fails. So I set Pocketcasts to only download episodes on my home network.
I've replaced Google Maps location sharing with Home Assistant, works great. I've set mine up to show the last 12 hrs history, so I get a nice path of where we've been that day.
So without having looked into it really, my assumption is that these podcast hosts will serve a specific file based on the response to an API call. If my Pihole blocks that call, they don't want to serve nothing, so they fallback to a file that sometimes has "generic" ads (often for US-based companies) or other times no ads at all. Of course this doesn't work for all podcasts, and as mentioned sometimes still has ads anyway. One day I might look more closely into it.