What does it mean "no access" for a smart lock?

About an hour ago, my Nuki Smart Lock says “no access” (as on the screenshot below)

I can’t:

  • lock/unlock the device
  • add/remove access codes
  • manage the device (rename, etc…)

I can, however, see that the device synchronizes every now and then (in a few minute intervals). Tried to remove/insert battery, did not help.

Anyone knows what does it mean?

More info: connection seems fine on the Android app. I can lock/unlock the device with the app. However, Web and API are not working…