I experience this issue for weeks at a time each time Steam decides a reauth to paypal is needed.

I log in to Paypal

It wants to MFA and I choose one and it does not even try...just get failure msg please try again later.

I see nothing in Paypal directly blocking Steam. Bought lots of Summer Sale games.

Very Annoying. It seems like Steams connection to paypal is jacked up in some way.