You are logged into eBay.ca Canada. Most likely because you viewed a Canadian seller listing from eBay.com and clicked on a link in the description that was directing you to eBay.ca and prompted you to login here to eBay.ca to view something in the listing. And you stayed here on eBay.ca. Not a problem, easy to fix.
All you have to do is log out of eBay.ca, close your browser, restart your browser and log back into eBay.com USA the way you normally do.
This seems to be happening fairly regular to ebay.com users, at least a couple of times a month now if not more. It was rarer 2-3 years ago. I wonder why.