Managed host could not connect to remote domain controller on JBoss EAP 7

Issue

One slave just disconnected from the master and won't connect. Other Slaves are configured the same and connecting without any issue.

Throwing the error:

WARN  [org.jboss.as.host.controller] (Controller Boot Thread) WFLYHC0001: Could not connect to remote domain controller remote+http://IP:9990: java.lang.IllegalStateException: WFLYHC0052: Could not connect to master in 0 attempts within 30000 ms
    at org.jboss.as.host.controller.RemoteDomainConnectionService.register(RemoteDomainConnectionService.java:307)
    at org.jboss.as.host.controller.DomainModelControllerService.connectToDomainMaster(DomainModelControllerService.java:965)
    at org.jboss.as.host.controller.DomainModelControllerService.boot(DomainModelControllerService.java:703)
    at org.jboss.as.controller.AbstractControllerService$1.run(AbstractControllerService.java:372)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.io.IOException: java.util.concurrent.CancellationException: JBTHR00004: Operation was cancelled
    at org.jboss.as.host.controller.RemoteDomainConnection.connectionOpened(RemoteDomainConnection.java:250)
    at org.jboss.as.protocol.ProtocolConnectionManager.connect(ProtocolConnectionManager.java:78)
    at org.jboss.as.host.controller.RemoteDomainConnection.connect(RemoteDomainConnection.java:147)
    at org.jboss.as.host.controller.RemoteDomainConnectionService.register(RemoteDomainConnectionService.java:288)
    ... 4 more
Caused by: java.util.concurrent.CancellationException: JBTHR00004: Operation was cancelled
    at org.jboss.threads.AsyncFutureTask.get(AsyncFutureTask.java:251)
    at org.jboss.as.host.controller.RemoteDomainConnection.connectionOpened(RemoteDomainConnection.java:244)
    ... 7 more

2020-03-17 16:51:04,065 WARN  [org.jboss.as.host.controller] (Controller Boot Thread) WFLYHC0147: No domain controller discovery options remain.
2020-03-17 16:51:04,065 ERROR [org.jboss.as.host.controller] (Controller Boot Thread) WFLYHC0002: Could not connect to master. Error was: java.lang.IllegalStateException: WFLYHC0120: Tried all domain controller discovery option(s) but unable to connect

On the ABC123 server (10.0.0.2) this Domain Controller and a node, and on the DEF456 server (10.0.0.3) there is a JBoss EAP 7.2 that we want to join to the domain controller. But look at the error that comes out in:

2020-11-19 14:02:15,819 DEBUG [org.jboss.as.host.controller] (MSC service thread 1-5) Starting Host Controller Server Inventory
2020-11-19 14:02:21,035 WARN  [org.jboss.as.host.controller] (Controller Boot Thread) WFLYHC0001: Could not connect to remote domain controller remote+http://IP_ADDRESS:9990: java.net.ConnectException: WFLYPRT0023: No se pudo conectar a remote+http://IP_ADDRESS:9990. La conexión falló
        at org.jboss.as.protocol.ProtocolConnectionUtils.connectSync(ProtocolConnectionUtils.java:130)
        at org.jboss.as.host.controller.RemoteDomainConnection.lambda$openConnection$0(RemoteDomainConnection.java:223)
        at org.wildfly.common.context.Contextual.runExceptionAction(Contextual.java:108)
        at org.wildfly.security.auth.client.AuthenticationContext.run(AuthenticationContext.java:273)
        at org.jboss.as.host.controller.RemoteDomainConnection.openConnection(RemoteDomainConnection.java:223)
        at org.jboss.as.host.controller.RemoteDomainConnection$InitialConnectTask.connect(RemoteDomainConnection.java:592)
        at org.jboss.as.protocol.ProtocolConnectionManager.connect(ProtocolConnectionManager.java:70)
        at org.jboss.as.host.controller.RemoteDomainConnection.connect(RemoteDomainConnection.java:147)
        at org.jboss.as.host.controller.RemoteDomainConnectionService.register(RemoteDomainConnectionService.java:288)
        at org.jboss.as.host.controller.DomainModelControllerService.connectToDomainMaster(DomainModelControllerService.java:965)
        at org.jboss.as.host.controller.DomainModelControllerService.boot(DomainModelControllerService.java:703)
        at org.jboss.as.controller.AbstractControllerService$1.run(AbstractControllerService.java:372)
        at java.lang.Thread.run(Thread.java:748)

2020-11-19 14:02:27,038 WARN  [org.jboss.as.host.controller] (Controller Boot Thread) WFLYHC0001: Could not connect to remote domain controller remote+http://IP_ADDRESS:9990: java.net.ConnectException: WFLYPRT0023: No se pudo conectar a remote+http://IP_ADDRESS:9990. La conexión falló
        at org.jboss.as.protocol.ProtocolConnectionUtils.connectSync(ProtocolConnectionUtils.java:130)
        at org.jboss.as.host.controller.RemoteDomainConnection.lambda$openConnection$0(RemoteDomainConnection.java:223)
        at org.wildfly.common.context.Contextual.runExceptionAction(Contextual.java:108)
        at org.wildfly.security.auth.client.AuthenticationContext.run(AuthenticationContext.java:273)
        at org.jboss.as.host.controller.RemoteDomainConnection.openConnection(RemoteDomainConnection.java:223)
        at org.jboss.as.host.controller.RemoteDomainConnection$InitialConnectTask.connect(RemoteDomainConnection.java:592)
        at org.jboss.as.protocol.ProtocolConnectionManager.connect(ProtocolConnectionManager.java:70)
        at org.jboss.as.host.controller.RemoteDomainConnection.connect(RemoteDomainConnection.java:147)
        at org.jboss.as.host.controller.RemoteDomainConnectionService.register(RemoteDomainConnectionService.java:288)
        at org.jboss.as.host.controller.DomainModelControllerService.connectToDomainMaster(DomainModelControllerService.java:965)
        at org.jboss.as.host.controller.DomainModelControllerService.boot(DomainModelControllerService.java:703)
        at org.jboss.as.controller.AbstractControllerService$1.run(AbstractControllerService.java:372)
        at java.lang.Thread.run(Thread.java:748)
...
...
2020-11-19 14:02:51,052 WARN  [org.jboss.as.host.controller] (Controller Boot Thread) WFLYHC0147: No quedan opciones de descubrimiento del controlador.
2020-11-19 14:02:51,052 ERROR [org.jboss.as.host.controller] (Controller Boot Thread) WFLYHC0002: No se pudo conectar al maestro. Cancelando. Error: java.lang.IllegalStateException: WFLYHC0120: Se intentaron todas las opciones de descubrimiento del controlador de dominios pero no se pudo conectar

or also:

...
2020-12-10 15:45:31,962 WARN  [org.jboss.as.host.controller] (Controller Boot Thread) WFLYHC0001: N'a pas pu se connecter au contrôleur de domaine distant remote+http://172.22.15.220:9990: java.lang.IllegalStateException: WFLYHC0052: N'a pas pu se connecter au master après 5 tentatives pendant 30000 ms
    at org.jboss.as.host.controller.RemoteDomainConnectionService.register(RemoteDomainConnectionService.java:307)
    at org.jboss.as.host.controller.DomainModelControllerService.connectToDomainMaster(DomainModelControllerService.java:965)
    at org.jboss.as.host.controller.DomainModelControllerService.boot(DomainModelControllerService.java:703)
    at org.jboss.as.controller.AbstractControllerService$1.run(AbstractControllerService.java:372)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.ConnectException: WFLYPRT0023: N'a pas pu connecter à remote+http://172.22.15.220:9990. La connexion a expiré
    at org.jboss.as.protocol.ProtocolConnectionUtils.connectSync(ProtocolConnectionUtils.java:130)
    at org.jboss.as.host.controller.RemoteDomainConnection.lambda$openConnection$0(RemoteDomainConnection.java:223)
    at org.wildfly.common.context.Contextual.runExceptionAction(Contextual.java:108)
    at org.wildfly.security.auth.client.AuthenticationContext.run(AuthenticationContext.java:273)
    at org.jboss.as.host.controller.RemoteDomainConnection.openConnection(RemoteDomainConnection.java:223)
    at org.jboss.as.host.controller.RemoteDomainConnection$InitialConnectTask.connect(RemoteDomainConnection.java:592)
    at org.jboss.as.protocol.ProtocolConnectionManager.connect(ProtocolConnectionManager.java:70)
    at org.jboss.as.host.controller.RemoteDomainConnection.connect(RemoteDomainConnection.java:147)
    at org.jboss.as.host.controller.RemoteDomainConnectionService.register(RemoteDomainConnectionService.java:288)
    ... 4 more

2020-12-10 15:45:31,962 WARN  [org.jboss.as.host.controller] (Controller Boot Thread) WFLYHC0147: Aucune option discovery de contrôleur de domaine restante.
2020-12-10 15:45:31,963 ERROR [org.jboss.as.host.controller] (Controller Boot Thread) WFLYHC0002: N'a pas pu se connecter au Master. Erreur: java.lang.IllegalStateException: WFLYHC0120: A essayé toutes les options discovery du contrôleur de domaine, et impossible de connecter
2020-12-10 15:45:31,964 FATAL [org.jboss.as.host.controller] (Controller Boot Thread) WFLYHC0178: Abandon avec code de sortie 99
2020-12-10 15:45:31,995 INFO  [org.jboss.as] (MSC service thread 1-1) WFLYSRV0050: JBoss EAP 7.2.3.GA (WildFly Core 6.0.15.Final-redhat-00001) arrêté en 27ms