Welcome to PayPal Community Forum and thank you for posting!
I am sorry for the inconvenience caused to you while adding a bank. I know the urgency to add your bank account to your PayPal account. PayPal's Security System monitors and detects many different factors to keep the network as secure as possible. In this case, you can try again at a later time. If the issue persists, you can try adding a different bank.
Best Wishes, Ayesha
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