I recently setup my ZigBee network in Home Assistant, using a Conbee III with deConz on my Synology NAS.

I purchased a few Aqara Temperature sensors and a couple of Mini Switches.

I was able to get them to pair just fine, but they won't remain online for more than a couple days. They then drop off and I can't even reconnect them easily. I need to try to pair them again like 10 times before they come back online.

At this point I don't know if the problem is my network, the Conbee III, deConz, or the Aqara devices.

I don't know much about ZigBee, but a couple things that I tried so far were:

1. Use a USB extender instead of connecting the Conbee III directly to my NAS.
2. Bring the devices as close a possible to the gateway. I don't have a big home, so I don't think distance is a factor here, but still, I put of the sensors right next to the gateway, and it would still drop after a while.

Do you have any hints on things to try to get this fixed, or at least identify the problem?