Soapui, Groovy problem with JSM connection

Hi!

I have a Groovy script in SoapUI Open Source (5.5.4) & Hermes 1.14 which keeps sending JMS message to an IBM MQ queue.

The relevant section of the code is the following (code is simplified just for the sake of readability):

 while (testRunner.testCase.testSuite.project.getPropertyValue('STOP'+n) != '1') {

requestHolder.setNodeValue("//soapenv:Envelope/soapenv:Body/Payment/creditor/AccountNumber",accountNumber);
testRunner.runTestStepByName('sendPayment' + n);

}

Multiple threads can be started with dedicated test steps (for example: sendPayment1 for Thread-1, sendPayment2 for Thread-2)

Based on the logic above we send continously transaction to a payment hub. 

So far we had no problems using this method, but after moving to the production environment I keep getting MQ connection problems. It seems we're having trouble connecting to the queue manager, and according to the logs it's network issue - although our network experts said there was no problem with the network and all server (including the one that hosts the QM) were available in this time period. 

Did anybody experience this phenomenon? 

My biggest problem is not the outage anyway, but that the script stops working and for a more-days-long test it's a showstopper. Is there a way to catch this outage in SoapUI Groovy script? Try-catch-finally didn't workd - I think the exception was handled by another built-in class. All I see - unfortunately hours later - a log entry and a broken sending process in the database.

Thanks in advance for sharing your thought with me on this issue!

BR, Csaba

ps.: And sorry for the foreign language in the log attached, I think error codes make understandable the excerpt.

ps2: At the same time the proble occurs a ....FAILED.txt file appears in the log directory with the following content:

Status: FAILED
Time Taken: 10133
Size: 0
Timestamp: Fri Nov 29 14:07:59 CET 2019
TestStep: initiatePaymentOTM1

----------------- Messages ------------------------------
[SOAP Response] Response is missing or empty

----------------- Properties ------------------------------
Endpoint: jms://HERMSESSION::queue_SOAPUI_WRAPPER_IN::queue_TEST__REPLY
Username:
Encoding: UTF-8
Password:

---------------- Request ---------------------------
Request Headers:

---------------- Response --------------------------
Response Headers: