mod_cluster INFO request hits read timeout after applying ssl-context to mod-cluster-config

Issue

• To set up https from EAP to httpd, we recently applied a ssl-context to the mod-cluster-config pointing to a server-ssl-context from the elytron config. After this, JBoss always sees a read time out for its requests and the requests are never seen by httpd:

DEBUG [org.jboss.modcluster] (UndertowEventHandlerAdapter - 1) Catching: java.net.SocketTimeoutException: Read timed out
    at java.net.SocketInputStream.socketRead0(Native Method)
    at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
    at java.net.SocketInputStream.read(SocketInputStream.java:171)
    at java.net.SocketInputStream.read(SocketInputStream.java:141)
    at sun.security.ssl.InputRecord.readFully(InputRecord.java:465)
    at sun.security.ssl.InputRecord.read(InputRecord.java:503)
    at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:975)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1367)
    at sun.security.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:750)
    at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:123)
    at sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:221)
    at sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:291)
    at sun.nio.cs.StreamEncoder.implFlush(StreamEncoder.java:295)
    at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:141)
    at java.io.OutputStreamWriter.flush(OutputStreamWriter.java:229)
    at java.io.BufferedWriter.flush(BufferedWriter.java:254)
    at org.jboss.modcluster.mcmp.impl.DefaultMCMPHandler.sendRequest(DefaultMCMPHandler.java:525)
    at org.jboss.modcluster.mcmp.impl.DefaultMCMPHandler.sendRequest(DefaultMCMPHandler.java:620)
    at org.jboss.modcluster.mcmp.impl.DefaultMCMPHandler.status(DefaultMCMPHandler.java:386)
    at org.jboss.modcluster.mcmp.impl.DefaultMCMPHandler.status(DefaultMCMPHandler.java:365)
    at org.jboss.modcluster.ModClusterService.status(ModClusterService.java:454)