Internal server results not arriving when sent from cable networked computer

I am using Captivate 9 and posting results to an internal server.

However the results only appear once for the same lesson if I send from a computer with a cable internet connection.

This is the situation:

Multiple submissions (from different learners) for the same lesson (desired outcome):

• When using a wireless connection (desktop or device)
• When published locally (not on the web server)
• When previewed locally in a browser (not on a web server)

Submission of data for the same lesson only arrives the first time:

• When data is submitted from the web server version of the tutorial from computers with cable network connections

My IT department say it must be a Captivate problem but given that the data sends when previewed locally or when using wireless I think there is something else going on.

Would greatly appreciate any ideas

Michelle