Be sure to read and try to follow all the advice here before troubleshooting any further → https://community.home-assistant.io/t/guide-for-zigbee-interference-avoidance-and-network-range-coverage-optimization/515752
(take note that also contains information/link about selecting Zigbee network channel/frequency range for you → https://www.home-assistant.io/integrations/zha#defining-zigbee-channel-to-use)
Then also read and follow these best practice tips for pairing as well → https://www.home-assistant.io/integrations/zha#best-practices-to-avoid-pairingconnection-difficulties
Combining everything in those three should at least remove any obvious things that can cause issues.