Hi there, we're sorry to hear you are experiencing trouble with deleting cloud synchronized videos from your Oculus app. We recommend starting by performing a reinstall of the app.
If you require further assistance, you can receive live chat support by clicking here and choosing the chat button on the bottom right corner. We're here to help! 🙂
I have the same problem on IOS. Delete your app and reinstall is not a good answer, it is always the go to answer. If you are implementing syncing you should also give us the options how we want to sync, not sync or remove synced files from the app. Oculus should do better or give better answers than just that. Disappointed.
You have to reupload the videos to your file transfer app, like android file transfer for pc, or mac I'm using. Then unsync the videos in the quest files app. If you delete them from the quest also there will be another error when you try to delete from the file transfer app. Just close it and they should be gone.