Seems that eBay doesn't 'see' the return tracking in the dispute - if you used eBay's return label or your own, that's what they look for. There is a bug that's been going on for a long time where the tracking doesn't load as it should.
Contact CS to help you with this if you can't upload it.
Go to this linked page below, click "have us call you" or "Chat with us"
