Some Zigbee Coordinator dongles do have better range than others when distant devices communicate diretctly to the Zigbee Coordinator and not going through the closest Zigbee Router device, but that should not matter as is not how Zigbee it meant to work, instead you are suppose to extend your Zigbee network by adding many Zigbee Router devices that that use mesh networking that take care of the total coverage. That is, the actual range between the Zigbee Coordinator and devices that connect to it directly should not matter as it should rwally only need to talk to the closest Zigbee Router devices, as all you should need to do is add more Zigbee Router devices (and maybe re-pair devices that have range issues if they do not automatically connect to a closer Zigbee Router device).
So if distant devices connect directly with the Zigbee Coordinator then something is wrong and you should probably try re-pairing that device to a closer Zigbee Router, but first add more Zigbee Router devices if needed. Personally I recommend buying a few IKEA Trådfri Signal Router devices (or reflash Sonoff Zigbee dongles with Zigbee Router firmware) and add them spread out in your house to act as the backbone of your Zigbee network with them creating the core of the mesh network.
I also mention that in this other best practice guidelines thread → https://community.home-assistant.io/t/guide-for-zigbee-interference-avoidance-and-network-range-coverage-optimization/515752
Zigbee technology uses mesh networking (a type of network topology/architecture), which means that most mains-powered devices are a “Zigbee Router” that can act as a signal repeater and range extended by transmitting data over long distances by passing data messages through the Zigbee network mesh of intermediate devices to reach more distant Zigbee devices. Thus the key to a great and healthy Zigbee network is to add/have many “Zigbee Router” devices relatively close to each other in order to achieve good coverage and range. So you more or less just need to add/have several mains-powered Zigbee devices in the network that act as “Zigbee Router” devices.
- Add more and decrease the distance between Zigbee devices in Zigbee network mesh to get better range and coverage:
- Zigbee uses mesh networking and depends on having many “Zigbee Router” devices to extend range and coverage:
- Recommendation is to add additional mains-powered Zigbee devices known to be good Zigbee Router devices.
- Add more Zigbee Router devices and reduce their distances to extend network mesh coverage and range.
- Note that not all mains-powered devices have firmware that makes them act as a Zigbee Router device.
- Some brands/models of Zigbee Router devices are known to only work well with the same brand of devices.
- Add more Zigbee Router devices and reduce their distances to extend network mesh coverage and range.
- Buy a few known good dedicated Zigbee Router products (for example the “IKEA Tradfri Signal Repeater ”).
- Search community forums for more “Zigbee signal repeater” or “Zigbee range extender” Zigbee Router tips.
- Buy a few additional new Zigbee USB adapters to use after re-flashing them with Zigbee Router firmware.
- Reflash/reuse modern Zigbee USB adapters to act as Zigbee Router devices by changing Zigbee firmware.
- Recommendation is to add additional mains-powered Zigbee devices known to be good Zigbee Router devices.
- Zigbee uses mesh networking and depends on having many “Zigbee Router” devices to extend range and coverage: