Hi Doug,
Thanks for providing us this information. Please provide us with the screenshot at your convenience so we can check the same.
Also, while taking a screenshot expand network adapters to check if driver for laptop Ethernet ports disables or goes missing when you connect the port replicator.
If it has worked earlier and recently stopped working then you can also perform system restore to resolve this issue:
Please perform these steps and let us know the results, so we can advise you further.