We have an ArcGIS license manager on a server on our network. We have to occasionally take the server down for maintenance, so we have the production team borrow their licenses so that they can keep working.
ArcMap will not launch using the borrowed license while still connected to the network (from which the license server has been removed). The program just hangs on the splash screen. However, if we unplug the machines from the network ArcMap launches without issue. If we then plug the machine back into the network with ArcMap launched, several features of the software operate more slowly (e.g. accessing feature properties). We need to maintain a network connection in order to work with data located on another server.
Is ArcMap ignoring the checked-out license because it thinks it can still find the license manager on the network?
Is there a way in which we can check-out the licenses and use them without having to disconnect from the network?
NOTE: The solution provided by @PolyGeo worked. I did end up having to have ESRI reauthorize our licences as we had to reinstall the License Manager while all licenses were borrowed, which ended up causing a conflict.