Nortek and mesh Zigbee

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”: