Have you upgraded Zigbee Coordinator firmware? → https://github.com/walthowd/husbzb-firmware
Anyway, you should note that it is based old decapitated hardware so you should really consider buy a newer adapter as it will never get any newer firmware that that older community build linked above.
Regardless, read and try to follow all the best practice this here on how to achieve a good stable mesh:
Also check out all the other Zigbee related community guided linked in this “Home Assistant Cookbook”:
- Is Zigbee right for you?
- Zigbee buyer’s guide
- Migrating from a Philips Hue Bridge to the ZHA (Zigbee Home Automation) integration
- Zigbee #1: where can I find a list of supported devices?
- Zigbee networks: how to guide for avoiding interference + optimize using Zigbee Router devices (repeaters/extenders) to get a stable network with best possible range and coverage
- Zigbee Guide: How-to setup local custom device handler quirks in ZHA integration
- Mains powered Zigbee devices that aren’t routers
- Zigbee devices that don’t play nice
- Not many people know that… A random collection of Zigbee trivia
- A to Zig - a Zigbee glossary
- Database of Zigbee devices supported by ZHA, Z2M and others
- Zigbee2MQTT (Z2M) supported devices