Hi jfalbo,

This might be happening if the network adapter is allowed to be disabled to save power on sleep. To uncheck the setting

1.       Open Device Manager
2.       Expand Network Adapters
3.       Right click on the Network adapter installed on your computer
4.       Go to Properties
5.       On the Power Management tab uncheck all the boxes and apply the settings
6.       Restart the computer and check if the network card works fine.

Please let me know if this helps.