If you look at your Luxion.log file by clicking License Folder within the Luxion License Server and open the Luxion.log file you will see the entry below. 

No valid hostids, exiting
EXITING DUE TO SIGNAL 25 Exit reason 2
LUXION exited with status 25 (Invalid host)
Please correct problem and restart daemons

It would be from your internet connection changing from Ethernet to Wifi, vice versa, your ethernet connection might have been enabled in one adapter and changed to another adapter. This will cause the HostID (MAC address) to change. To help you get this issue resolved would you be able to send us a copy of your KeyShot floating license and the information from the instructions below?

How to find your System's HostName and MAC address
1. Open the Windows Command Prompt and type ipconfig /all.
2. Press Enter.
3. Your HostName will be at the very top under your ipconfig /all command.
 . Your MAC address is the Physical Address of the connection that is Enabled and Preferred.
1. Open the Terminal application and type HostName.
2. Press Enter.
3. Your HostName will be displayed under your HostName command.
4. Next type ifconfig.
5. Press Enter.
6. Your MAC address will be show on the list.
7. Send us a screenshot of the Terminal window.