Sometimes a PayPal payment doesn't register in Simplero, even though it's gone through in PayPal.
The way Simplero knows that the payment has gone through is that PayPal sends us what's called an IPN, short for Instant Payment Notification.
Without this, we have no way of knowing the transaction went through.
So if this doesn't get to us, that's a problem.
What you need to do is contact PayPal and ask them to look into it. I don't know much about how PayPal works, but hopefully they do, and they can fix it.
It might be a setting on your account that you can turn on or off IPNs, or it may be that something happened that they can fix and do something about.
Whatever it is, this is what you need to do: Get in touch with them, and make sure the IPN is sent for all transactions originating with Simplero.
The URL that they'll be sent to will be something like
with 1234 being the transaction in question.