The ListenBrainz app doesn't work anymore since September on Android 7 and lower due to the change on the certificate.

As consequence, also no other scrobbler app works anymore with Listenbrainz on those devices.

https://github.com/kawaiiDango/pano-scrobbler/issues/418

Technical details here:

https://community.letsencrypt.org/t/letsencrypt-certificates-fails-on-android-phones-running-android-7-or-older/205686

Note there are tons of devices using Android 7. Not talking about phones but DAPs, like Fiio M11 and all that. Which are specifically designed to play music and now are totally out of the equation.

Not sure what suggestions offer to fix it, but maybe it's possible to establish the connection skipping ssl cert verification in this case (giving a warning first on Android 7- devices). Web browsers allow to do that and the web works fine.