VEGAS 365 can be activated on 1 computer at a time. For a different computer, deactivate the existing one and activate the other.

The MAGIX Sales Dept. replies to my enquiries June/July 2019 put it a bit differently:

"The software VEGAS 365 can be installed only on one computer" and "can be deactivated in the same ways that the standard license can, either from your account or from in the software itself." 

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. OR 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."

From https://www.vegascreativesoftware.com/us/vegas-pro-365/ product page, payment plan 1 month, Purchasing details: "Subscription and cancellation conditions: VEGAS Pro 365 will be available immediately after payment and activation. The charge for the minimum term is payable as a single sum upon conclusion of the contract. The minimum term begins on the date of purchase. If you cancel your order within 14 days, you will receive a complete refund. The contractual period of VEGAS Pro 365 will be automatically extended by one month at a time until you cancel the agreement You will be informed well in advance if the extension rate or taxes included change. A cancellation is possible up to 1 day before the end of the contract period. To cancel the contract, please send an email stating your customer number to: infoservice@magix.net"

Note also this: "ONLINE LIVE CHAT : pre-sales and registration help is available via online live chat from 12pm-4pm U.S. Central Standard Time [weekdays]. Go to https://www.vegascreativesoftware.com/us/support/ and click the chat bubble in the bottom right corner." (It's on at the time of writing this.)

You could also try and ask a pre-sales question here: infoservice@magix.net

@Mark-Hidasi