If the communication is not working properly a restart of the integration might work, but not in this case.
Bur you are right trying to restart the MQTT feature on the lock side does not work.
Anyway - I have played around with the battery power mode, but both locks have the same setting (automatic) and the same FW (4.2.8).
I will monitor this on my two locks and will report back.
I guess I will need another 1-2 weeks to get reliable results though.
In the past one of the locks went to unavailable and it took sometimes several hours (I suspect the Wifi repeater re-initializing to trigger a re-connect).
For now I can say, that the recent disconnects (3 since the update) have been resolved within 10 seconds - so I am positive that the MQTT connection has improved.
By the way, the NUKI App in these cases still showed the Wifi connection to be ok (so did the router).
So, it was obviously just the MQTT communication.
Today I connected my nuki smart lock as a matter device. It is working with the HA companion app. Since thread and matter is meant to be a system with lower battery consumption than wifi, I shutdown the wifi from de lock. Unfortunately in that case I can not use the native NUKI app but only HA companion app. If you ask me it is contradictory.
FWIW, my Nuki (Smart Lock Pro 4) works with the Nuki app over Matter in addition to the HA control. I’ve never connected it to WiFi, here’s how the app displays the connection:
