I have run into this with RMI when the IIOP listener address was not configured (the default is 0.0.0.0). That's just a stab in the dark though. We'll need more info.
What type of application are you running: web client, or remote ejb?
Maybe pull a thread dump on the standalone when it's locked.
https://visualvm.dev.java.net/threads.html
I bet you'll see a bunch of threads in monitor state (all waiting for some thread). The thread they're all waiting on can give a clue what's going on.
Regards,
Jim
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