Let not eBay's left hand know what eBay's right hand is doing

So I try to sign into my eBay account, but apparently my password - the same password I've been using quite a lot lately, bidding on baby stuff - is incorrect. So I try to reset.
I get an email with a link. I click the link. It wants my username. I enter it.
It tells me that is an invalid username.
I check it. I check the username in the eBay email, just to be sure. It's definitely the right username.
I copy/paste the username from that email.
Still invalid.
I click on "Get help". It is not helpful.
I enter eBay as a guest so I can look for more help. I click "contact us".
It bumps me back to the login page. I guess only eBay members are allowed to contact eBay.
I am an eBay member. I am currently bidding on a number of items, in fact. I know perfectly well what my username is, and I'm pretty sure of my password too, but eBay doesn't believe me. Even though its own emails use that name.

Conundrum.