If it has not changed recently, the license works only on one device at a time.

"There are 2 ways to deactivate a device so you can activate a different one:

Visit your MAGIX account > My Products > Show More Details > Deactivate. This option can be used only once a month.

From the VEGAS Pro Help menu choose Deactivate the Software on this PC. This option can be used as often as you wish. An internet connection is required."

The perpetual ("forever") license allows the use on two devices simultaneously.