Are you using Chrome and searching on the Advanced Search page? If so, you may be running into an issue where your username is being inserted into the seller search field and results are only being shown from your items (if any). Deleting your eBay credentials from Chrome's password manager using the link in that seller drop-down menu can fix that issue for you. Adding the credentials back when you sign in again seems to work and not re-trigger the issue.
If that is not the issue, can you describe what you are doing and seeing?
