Latitude 5480 Windows Boot Manager doesn't default to drive

The hard drive in my 5480 will be the boot device as long as I'm not plugged in to my docking station.  As soon as I restart and plug into my docking station, it attempts PXE boot first and fails, even though WBM is my first option.  I've gone in and disabled legacy options and confirmed that Windows Boot Manager is my first option.  Please advise.