After my iPhone rebooted at home after the battery had charged, it opened the door after ~ 3 minutes. According to the release notes delivered with 2.12, this behaviour should not happen.
The timeout is currently set to 2min. Please send a log to developer@nuki.io from within the app (Menu > Help > Error Log). Please also switch on debug mode if you haven’t done that yet.
You sent the log already yesterday to our support. Found it. Thanks!
Time between restart and unlock was 4min in your case. We’ll perform more tests and eventually raise the timeout if this is a common delay.