Sometimes, the store’s WiFi is slower than a snail on vacation. If your payment takes forever, just wave your phone in the air. It helps? No. But it makes you feel active.
Also, make sure your PayPal balance actually has money in it. I once tried to pay with a balance of $0.02. The cashier just looked at me, and I whispered, “It’s the principle.” It didn’t work.
Another tip: link a backup card to your PayPal account. That way, if your primary balance is empty, PayPal can pull from your credit card. It’s like having a financial safety net, but without the awkward circus trapeze.