Hi @jwbaker
Welcome to the Sonos Community!
Looking at your diagnostic, I see you have no Play:3s, but you do have a Play:1. I’ll assume that’s the speaker you’re having the issue with. Although it is reporting decode errors (I think the reported changes in bitrate might be what you’re actually hearing - if there is no such change, then the stream will not be played correctly and will sound like the non-audio data you mentioned), they likely stem from the WiFi transmission errors also reported. I recommend you read our reducing wireless interference help page and remove any sources of interference from within 1m of both the speaker and the router (keep in mind what might be on other sides of walls).
I’m also seeing DNS resolution issues which might be a result of those same transmission errors, but I’d still recommend you reboot your router by removing power for one minute, and repeating this several times a year.
I hope this helps.