Manual open doors itself ! Big security issue?

My new Nuki 2.0 opened the doors itself.
Before doors closed , lock locked. Then nuki opened doors itself with message manual open!!! It happened when delivery guy where standing on opposite side of the door so my wife saw it and he saw it ! He said the doors just opened when he ring normal bell.
This is very scary and see happening to others !
What and where send ? Which number to call to get help ?We feel not save now.

Bridge, fobs, iphone, android samsung, Nuki web, homekit.
Don’t have now smart ring just normal door bell.
And the log says manual open so it’s very weird.
Delivery guy ring the door bell.
Nuki manually open the door, message says manual door open but nobody pressed the nuki and when it has to happen 2 times. Door were locked closed before.
So my wife heard some noise and went down and see deliver guy pushing in our heavy package.
He assumed we opened the door for him so he start pushover our package. He said doors just unlocked.
Now today also get many motor blocked errors when I closed the door and press lock in nuki. Very annoying and not good. We don’t know if we can trust the nuki lock.