On a self hosted configuration, in the invoice view => more actions => view payment.
The link points to http://localhost/payments/$id_invoice instead of http://ip_of_system/payments/$id_invoice.
I’ve seen the same issue elsewhere but I can’t remember where. I’ll post it if I find it.
The localhost value seems to come from Settings => System Settings => Application Settings => URL, but this field seems to not be updatable. Also, the field should accept values like: http://some_ip:some_port
IN version 4.5.18