I just had an unrelated login problem myself
make sure you clear your browsing data, cookies etc (7 days worth)
then turn off computer- restart
then make sure you log in by putting Ebay in the top search bar - not google or other
make sure it has the Lock secure icon first in the address so you are on the real ebay site
see if you get a fresh connection that way -
if not try another browser.
My IT guy actually had me disable my eset for 5 minutes was able to log back on as the sign in page hadnt been coming up - then we immediately turned eset back on - I logged off, logged back on and it worked - good luck - if that doesnt work I would call ebay or get a tech savvy friend to help you
