The issue was fixed, albeit temporarily, and the thread now closed. But I'm getting the issue again. I'll start the cast, the device will behave as if it is casting but I won't hear anything out of the chromecast audio itself. When it does connect, I'll then get drop outs for 20-30 seconds at a time then the music will start by itself, often skipping to the next track without finishing the first.
I should note that I have groups set up for chromecast for multiroom audio but this issue normally occurs when I'm casting to an individual device rather than a group. Most of the time when casting to the group it has been fine, but I've experienced the issue in that scenario too.
The issue is intermittent. it happens roughly 50% of the time when casting.