Quite tricky for fellow buyers and sellers to guess without any details
How long has this been happening?
Have you tried the usual (clearing cache/cookies/using a different browser)
Are you on the app or the full site?
A couple of weeks back there were a few buyers having an issue trying to log in to PayPal, I can't recall how they worked it out
You might need to contact PayPal if nothing suggested by other members works for you
