Is this an external web service? If it is, maybe your firewall settings are preventing the port from communicating with it. Check with your infrastructure team on that.
If it's an internal web service, if I were you, I would still get the infrastructure team to monitor the network packets to make sure nothing is being lost.
Or maybe something has changed with the web service itself since you said the port used to work previously, you might want to double check that web service.
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