Can't download/stream from feed (Source is Podgrab via Cloudflare tunneling)

[Marlowe]

App version:
2.7.1 (d5f0ef244) :Google Play

Android version:
13 (Graphene OS)

Device model:
Pixel 5a

Expected behaviour:
Added RSS from Podgrab (via cloudflare tunneling). The tunneling works, I can listen to the podcasts via browser outside of the local network. I expected that I could do the same on the app.

Current behaviour:
The episodes show up in the feed, but cannot be downloaded or streamed. I got these errors (different attempts):

java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.

failed to connect to /x.x.x.x. (port 443) from /y.y.y.y.y (port 38392) after 10000ms

Just to be clear, the source works on the browser elsewhere

First occurred: Today

Steps to reproduce:

1. Install Podgrab via docker.
2. Set up Cloudflare tunnel (in my case, with the Home Assistant add-on “Cloudflared”).
3. Open the Podgrab site now and copy the RSS.
4. Add RSS to Antennapod and try to download/stream items in the list.