With only 1 active reservation, if you attempt to extend a reservation that currently active and the timer is counting down, you get the following error
Failed to Extend Environment
You are not allowed to perform this action. Reason: 'Max. active envs. policy: "You have reached the maximum number of active environments allowed (1). Please try again after terminating your currently active environment."'
(example: if I activate and have a reservation that is active for 2 hours, and I decide I would like to extend it for an additional 5 hours, the system doesn't allow it)