Maybe you have some rouge Zigbee Router that do not forward all messages, read → https://www.home-assistant.io/integrations/zha#best-practices-to-avoid-pairingconnection-difficulties
Good idea to add a few known good Zigbee Router devices as mentioned in the guide → Zigbee networks: how to guide for avoiding interference and optimize for getting better range + coverage
Not ”maybe”, it was me that put that info in bellows readme and in the ZHA docs 