Hi @AlfieIndie, welcome to the Sonos Community!
I’m sorry to hear that you’re having issues with Bandcamp on your system.
I’ve asked a colleague to try and they aren’t noticing any issues when searching through their collection or with playing tracks. If you haven’t, I would recommend reauthorizing Bandcamp on your system by going to the profile section of the Sonos app then to Content Services → Bandcamp → Primary Account → Reauthorize Account. After doing this, check if your collection shows and that tracks play correctly.
If this doesn’t help, try with another controller such as another phone, a PC, or the Web App. If you still can’t see your collection, then please reach out to our support team for further troubleshooting assistance.
I hope this helps!