Do you have any zigbee routers (generally, mains powered zigbee devices) on your mesh, or are they all battery powered?
The error you’re seeing is because the coordinator can’t communicate directly with your sensors due to distance and/or interference. Finding out what device this error relates to won’t fix your issue, but adding a few zigbee routers will.
Read up on this and make sure to follow the recommendations within - hopefully that’ll solve your issue.