Hello,
I was struggling with this same problem, receiving the below error message every time an order was placed using PayPal:
“You don’t have permission to access /checkout/order-received/7185 on this server”
For some reason, it began to happen after Paypal changed the old redirect page (the 10 seconds redirect page) to a new one.
I contacted PayPal letting them know about this. However, their help was pretty much useless (as usual). However, I was sure it was some kind of Woocommerce problem and apparently, it was indeed.
After placing several orders, changing several parameters in Paypal and Woocommerce. I solved the problem by changing the Invoice Prefix from the default to another one under Woocommerce’s PayPal settings.
Best regards,
Gabriel