Internet connection must be maintained while using Ansys so that the software can have constant communications with the License Manager. If your machine loses connection for any reason, the increments which it was using should be returned (checked in) back to the license manager. If not, please make sure there are no ghost processes running on the client machine that could be using any license.
Some possible workaround for this include:
1.) Making sure the software is closed before leaving the machine idle for a long period of time to make sure all licenses are properly returned before the machine times out.
2.) Setting a longer period for the machine time out if left idle
3.) Requesting a license with "Borrowable" increments from the Account Manager (however, this may come with other complications as "borrowing" a license will completely pull it from the server until it is returned, making it inaccessible by other users).
For more information, please see the link to the post in the forum below. Please feel free to let me know if you have any additional questions.