Unable to see my device using Airplay

I have a device that’s online, and that claims it’s running all services fine, but I can’t connect to it via Airplay. I don’t see it as an available source from either my iPhone or my Macbook. Full disclosure - I am completely new to using Airplay, so I very well could be doing something silly. The device does connect fine over Bluetooth, and it works properly.

Here’s the status panel of the device summary:

This is what it looks like in my iPhone when I list Airplay sources:

This is what it looks like in the Macbook (running Mojave, due to some old plugins). Note that I have a Bluetooth connection, but not Airplay:

The actual device is a Raspberry Pi 4 using the latest image as of Monday.

balena-sound_dull-tundra-30.09.21_13_41_13_(-0400).txt (7.8 KB)

Attaching a log in case that helps. It continued with “Waiting for audioblock to start…” messages after this.

Anybody? Is there a better channel of communication? I don’t mind RTFM if someone can just point me to TFM to R.