Your configuration of the memory management is correct.
However, we are not able to confirm that the cause of the problem is a memory shortage. The memory issues may be just the final consequence of a completely different problem that triggered an abnormal sequence of operations in the Server.
In fact, at the moment we lack any information on the history of the execution that led to the final problem.
Hence, I'm afraid I can't provide you with any answer different from #3 above, where I asked you to collect monitoring statistics throughout the whole life of the Server.