Headphone issues with OptiPlex 5040 model

We have been replacing workstations at our college with OptiPlex 5040s. We are running Windows 8.1 Enterprise x64. We use SCCM to image and have the latest Deploy OptiPlex 5040 Windows 8.1 Driver Pack loaded so the audio driver is current.

There have been many reports of students not getting audio from their headphones in the labs that have been upgraded to OptiPlex 5040 model. When I would head over to a lab and test a few random PCs (because the reports I was getting didn't include actual station designations), they would all work fine. I would plug in my 3.5mm plug earbuds and would get the audio popup asking what type of device I plugged in. Headphones is the default and so I would click "ok" and a few seconds later, the audio controls in the Windows taskbar would re-enable and sound would work fine through the headphones.

What I discovered was that if a student used USB headphones and then left the lab then another student comes in and plugs in 3.5mm headphones, they will not work unless the run the "troubleshoot sound problems" option from the task tray.

Anyone else experience this issue? Hopefully Dell is aware of this issue. All of our previous OptiPlex models had two audio ports (mic and headphone) and never seemed to have this issue.