Hi Chris,
I guess all Xiaomi / Aqara devices are not 100% compatible to the ZigBee standard.
I have some window / door sensors and I have the same problem, they are offline after about 1h.
I have a Telegesis dongle, and I see a TelegesisDeviceLeftNetworkEvent coming from the dongle after about 1h after the sensors has been discovered.
As a quick hack, I disabled removal of the node when this event is received, and the sensor works well afterwards. Of course the node service discovery runs into a timeout all the time, but basically the sensor still receives updates and is working quite reliable.
I’m not that familar yet with the code, but do you see any chance of setting some devices manually to online and disable online/offline handling completely? I’d love to see that I can simply set the nodes online after pairing.
I can contribute some code, but I need some hints on how something like that can be achieved.