Normally, if you have enabled the auto keystone correction feature, after you move the projector, it should get another keystone correction.

But if it does not have the keystone correction automatically, please try to adjust the sensitivity to see if it helps. 

Go to Settings > Projector > Advanced Settings > Motion Settings and choose high sensitivity.

If the above solutions cannot solve your issue, please contact Nebula Customer Support at support@seenebula.com for further assistance.