Unfortunately, this phenomenon can happen during transport when there are heavy vibrations. We will optimize the mechanism and packaging in future batches to prevent it from happening.
Luckily, as long as the key is still attached to its spring pivot at the back, you should typically be able to put the key back into its regular position. Rest assured that letting the key snap back in won't harm the mechanism and has no negative side effect in the long run.
Typically, only white keys are concerned. In this case, please put a finger at the end of the all-black key levers and push the affected key towards you, while at the front take the key on the sides with your thumb and index finger and pull it towards you. You should feel a spring at the back of the mechanism, giving way a bit to the key. While pressing from behind, move the key downwards to make it hop over the so-called "limit stopper". Let go when it's at the same height as the other keys. Here's a video of the process needed for white keys: https://www.dropbox.com/s/bibongj3rpe0ckj/keyHopOverLimitStopperFix.mp4?dl=0
In seldom cases, a black key may be protruding. Their limit stoppers are oriented in the opposite direction. Therefore, when snapping a black key back into its regular position, you will need to push it away from you in order to overcome the limit stopper it hopped over in the first place.
⚠️Make sure never to pull up already raised keys further, as this will provoke a detachment of the key from its spring pivot at the back. If this happens, the key will become completely loose. It will then be necessary to remove the aluminum top plate to access the pivot at the back and put the spring back in place. This makes you eligible for a return procedure, but if you are OK with investing 20 minutes for a repair, feel free to get in touch by opening a support ticket. We can provide information on how to disassemble Osmose and put the spring back into its place.