@shidemo same here 
Same issure, after mqtt reboots, nuki doesnt do reconnection… Really? same issue opened in april 2023, and was not checked? omg…
today a new firmware was released, for now after some tests seems that at least the issue when the wifi goes off and the nuki cant reconect to mqtt has gone, now reconnects fine 
, we will see
This firmware looks strange for me because I have no entry in the log specifying when the update was installed. Also there is no release note at all for this version, which is not usual.