2 questions. Can I get rid of/delete TV from your sources and delete Your services completely?
also, will the thumbnails ever work properly? Or how do I get them to work properly?

2 questions. Can I get rid of/delete TV from your sources and delete Your services completely?
also, will the thumbnails ever work properly? Or how do I get them to work properly?

Best answer by Airgetlam
No.
You’ve got some sort of issue grabbing thumbnails, it’s either timing out when polling your streaming service, or if they’re local files, there could be no thumbnails associated. I’d start with a simple network refresh, by unplugging all your Sonos devices from power, then rebooting your router. Wait two minutes, then plug back in your Sonos. Wait another two minutes and then check for updates in the controller. It will catch any outstanding updates, be they speaker or controller based. Then test.
If the issue continues after that, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it. Don’t post the resulting diagnostic number here, they get sensitive about GDPR.
There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.
When you speak directly to the Support staff, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.
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