If you go to My eBay > Account > PayPal Account, it will show you the PayPal email address linked with your account, however the address payments get sent to are listing-specific (meaning you can actually enter whatever address there you like, even multiple different ones over different listings, and the linked PayPal account doesn't guarantee that's the address used in the listing).
To adjust the payment address in any current listings, you'll either need to edit them one by one or through a bulk edit. (If you need guidance for either option, let me know and I'll post the steps to take).
If / when creating a new listing, just scroll down to the payments section and check the email address there, then update it if it's incorrect - this should ensure any subsequent listings have the updated address, as eBay typically auto-fills the last address used, but double check them just to make sure.
