Thank you for your post and welcome to the Community Forum!
I understand your concern regarding the negative balance. Whenever you make the payment, PayPal will instantly transfer the funds to the recipient and then would retrieve the funds from your funding source. It is possible that when we try to get funds from your funding source, the amount would have been declined by your bank. That might be the reason the balance became negative. If you want to know about it in-depth, kindly reach out to our customer support team through the options available on our website so that our advisors can look into your account and help you accordingly.