Hey @KatePlayItVR you have actually found a bug! There are a few different scenarios for starting reservations.
If you start the session before the scheduled start time then the full amount of reserved time will run and the reservation shifts so it will end before the originally scheduled end time.
If you start the session after the scheduled start time then it will cut off the time that has already passed from the original start time and run until the scheduled end time slot. This is to avoid creating conflicts with upcoming reservations so it runs the remainder of the reservation rather than shifting the end time and potentially running into another reservation.
The bug is that the "Now" function is not working correctly. If you click into the full reservation and select "Now" for the start time when starting a late reservation it should shift the reservation like in the example #1 above but it's doing it wrong and cutting off the time like in example #2. Jamie is already on the case and working on getting it fixed.
Thanks so much for bringing this to our attention!