Is Voidwalk Broken?

[Malficar]

Hello, i am new, and while playing a deck against the AI, i used Voidwalk, a cipher card which is suppose to exile a target creature until your next endstep, i activated it's ability and exiled a creature, but, they never returned at my endstep, anyone able to tell me what went wrong, i am a bit new to the Xmage program so i may have missed something
Malficar

TheElk801: Fixed beyond 1.4.26V8