Server 2 Server Config

I am trying to get S2S working between 2 domains.
Srv1.domain1.local
Srv2.domain2.local

I can ping domain1.local from domain2.local and Domain2.local from Domain1.local.
Also, I can do the same thing from each server using FQDN(Srv1.domain1.local <–> Srv2.domain2.local)

The domains are connected through an IPSec/IKEv2 VPN. I have configured the Firewalls to allow traffic on port 5269 and 5270.

Both sites use LDAP to authenticate users.
There is also a 2 way Trust between the domains. So users on domain1 can access all resources on domain2 and vice versa.
Both sites also have their own MySQL Database.

I whitelisted the to servers to each other and even tried Allowing All Servers. However, when I try to add a user that is connected to Srv2.domain2.local from a workstation connected to Srv1.domain1.local, no connection is established.

Is there a complete guide to setting this up?
Does anyone have any idea what I am missing?

I am making progress. But I have no idea what any of this means. From the other side, the test just flat out fails. Claims it can’t find the remote server.
From Srv1.domain1.local to Srv2.Domain2.local I am now getting this responce:

Sending server to server ping request domain2.local
Successful server to server response received.
Primary packet routing failed
org.jivesoftware.openfire.PacketException: Cannot route packet of type IQ or Presence to bare JID:
at org.jivesoftware.openfire.spi.RoutingTableImpl.routeToLocalDomain(RoutingTableImpl.java:306) ~[xmppserver-4.5.2.jar:4.5.2]
at org.jivesoftware.openfire.spi.RoutingTableImpl.routePacket(RoutingTableImpl.java:239) [xmppserver-4.5.2.jar:4.5.2]
at org.jivesoftware.openfire.server.OutgoingSessionPromise$PacketsProcessor.returnErrorToSender(OutgoingSessionPromise.java:343) [xmppserver-4.5.2.jar:4.5.2]
at org.jivesoftware.openfire.server.OutgoingSessionPromise$PacketsProcessor.addPacket(OutgoingSessionPromise.java:361) [xmppserver-4.5.2.jar:4.5.2]
at org.jivesoftware.openfire.server.OutgoingSessionPromise$1.run(OutgoingSessionPromise.java:134) [xmppserver-4.5.2.jar:4.5.2]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_251]
Failed to establish server to server session.