Do you have any mains-powered (plugged into the wall) ZigBee devices?
If yes, then they are probably ZigBee repeaters, which are devices that act similar to a WiFi extender, but for a ZigBee network.
Unfortunately, a majority of ZigBee repeaters do not allow Xiaomi / Aqara devices to remain connected. Only a small number of ZigBee repeaters are considered as "compatible" with Xiaomi / Aqara devices. There is a lot of detailed and helpful information in this thread (make sure to read all of the first post in the least):
I realize that I should make a clear warning to users in my opening post of this thread that there are "incompatible" ZigBee repeaters, and very strongly recommend them to read about that in the other thread I started on pairing Xiaomi / Aqara devices and keeping them connected.
I am going to make edits to my opening post here, and probably rename that other thread. My apologies for any confusion.
Yes, I would have bought an XBee module anyhow even if I didn't have a single Xiaomi / Aqara device, just because of the ability to easily look at the ZigBee network routing map and signal strength.
But yes, I can totally understand your "pain" budget-wise. I would not have bothered with Home Automation if not for Sengled bulbs and Xiaomi / Aqara sensors and buttons.
The XBee ZigBee module is a USB "developer" board, and with firmware that can be flashed and then custom settings sent so that it can be paired to your ZigBee network as another device - but all it does is act as a repeater (for any ZigBee devices, not just Xiaomi / Aqara.)
If it's connected to computer, then you just fire up the company's XCTU software and turn on active ZigBee network map scanning to see how all the devices are connected - either directly too the hub or via a repeater (including the Xbee itself).
There's lots more information about the Xbee on the other big Xiaomi thread we keep mentioning and especially the Everything Xbee thread here.
