When fusing a hybrid dinosaur in the creation lab, please make sure to either PLACE the hybrid on your park, or STORE it in the repository. At this time, please do not cancel the placement of the hybrid by tapping the red X button. This will cause your hybrid to disappear. Our team is fixing the issue but in the meantime please either PLACE or STORE them.
UPDATE 1.19.0
If you cancel the placement of your hybrid, it will go back into your creation lab or hatchery! Simply return to the creation lab or hatchery to retrieve your hybrid and place it on your park whenever you're ready!
If your hybrid is still missing due to a cancelled placement please contact support for further assistance.