I have an Aqara temperature and humidity sensor. The sensor goes offline numerous times a day and then comes back online. At first I thought the problem was the distance between the hub and the sensor but in the same room as the hub it produces the same thing.
When paired with the aqara hub it works uninterrupted.
I recently replaced 3 of my Zooz ZSE42 Zwave water leak sensors with the Aqara Zigbee water leak sensors (SJCGQ11LM). I’m using the Mariano Zigbee Moisture Sensor MC driver. All 3 of these will go offline at the same time and come back online randomly. I just checked and all 3 were all offline, brought one of them near the hub and pushed the button and it woke up and is online again (The other 2 are still offline). I have a mix of Zigbee and Zwave devices around 50 of each, so the mesh should be strong, in fact I have a Zigbee repeater within 4’ of this sensor.