CarPlay does not like Podcasts

My iPhone se [2nd gen.] has issues with car play. I have a 2018 Subaru legacy , with a 2023 replacement radio, which accepts car play.

Some times,volume goes to zero.

But most annoying is with podcasts.

My understanding is the podcast is DOWNLOADED to my iPhone. [I know I can listen to podcasts , while not in car].

I live in condo with underground garage. When I am playing podcast and go into the garage, it keeps playing. No problem.

But when I leave, car play won't start while in garage, or for several minutes after I leave. I get a message, something about not being connected to the internet.

Sometimes, it will not start for 20 minutes or more.

So why does iPhone or Car Play, keep telling me I have to download the content?

Any ideas? Thanks for your help?

NOT APPLE PODCASTs.