I am a noobie. I would like to post a pair of tips that confounded me for a few hours in an otherwise simple set up.
1st. I am running a basic Rpi 3, my network is a eero, my audio system is vintage 1990 audiophile (when I was a single man with too much income).
It took me two hours to figure out the Rpi could see networks with SSID names that were incompatible. I needed to remove an apostrophe from the name. Yes ALL non-letter or number characters are a problem.
Next you will need to be on the exact network as your Runeaudio. So you can't control the rune from the guest network.
OK that is all have got. But I thought I would post it to help the next noobie.