Do you have a "Loopback Zone" defined in the "Network Zones" settings as indicated in attached image?
If not than create it and add/edit the Firewall rules of your apps to connect as follows:
Action: Allow
Protocol: TCP
Direction: Out
SOURCE ADDRESS: Any Address
DESTINATION ADDRESS: "Type -> Network Zone", "Zone -> Loopbak Zone"
SOURCE PORT: Any
DESTINATION PORT: Any
127.0.0.1 is equal to 127.000.000.001 and display depends on the input field (see attached image too).