Are you deploying the Unlock Fixlet as part of a baseline?
According to the documentation:
Baseline components are not exempt from action locking because they can come from different sites.
So that could be the reason your action is failing. You may need to push as a single fixlet action.
If you are familiar with the REST API, you could push the unlock-lock fixlets from the BES support site, this will require more engineering and development from your side but may be the safest and more automated approach.
Another option and an old trick is to use a registry key on the windows computer where the console is running on and “bypass” the lock status.
I would be careful with this option as once enabled you will be able to push all type of content.